Attachment unit and endoscope

ABSTRACT

An attachment unit includes a tube main body extended along a longitudinal axis in a state that a gap is provided between itself and an outer peripheral portion of an insertion section or a member on the outer peripheral portion of the insertion section, and a tube proximal end portion, provided to a proximal direction side of the tube main body, to which a proximal end of the attachment unit is placed. The tube proximal end portion includes a proximal side gap reducing portion eliminating or reducing the gap as compared with a part to an inner peripheral direction side of the tube main body between itself and the outer peripheral portion of the insertion section or the member, and is placed to a distal direction side of an insertion opening in a use situation.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a Continuation Application of PCT Application No.PCT/JP2011/063944, filed Jun. 17, 2011 and based upon and claiming thebenefit of priority from prior U.S. Provisional Applications No.61/473,372, filed Apr. 8, 2011, the entire contents of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an endoscope including an insertionsection configured to be inserted into a lumen, and an attachment unitthat is attached to this endoscope.

2. Description of the Related Art

US 2010/0076264 discloses an endoscope including an insertion sectionwhich is configured to be inserted into a lumen, and an attachment unitwhich is rotatable about a longitudinal axis with respect to theinsertion section. The attachment unit includes a tube main body, and afin portion spirally provided on an outer peripheral portion of the tubemain body along the longitudinal axis. Further, a ring-like rotor isdisposed on an outer peripheral portion of the insertion section to berotatable about the longitudinal axis with respect to the insertionsection. The attachment unit is disposed on the rotator in a fixedstate. Therefore, when the rotor rotates, the attachment unit and therotor integrally rotate about the longitudinal axis with respect to theinsertion section. Furthermore, at a position where the rotor is notplaced in directions parallel to the longitudinal axis, a gap isprovided between the attachment unit and the outer peripheral portion ofthe insertion section, whereby rotation properties of the attachmentunit with respect to the insertion section is improved. Therefore, ateach of a distal end and a proximal end of the attachment unit, the gapis provided between the attachment unit and the outer peripheral portionof the insertion section.

When such a configuration, when the insertion section of the endoscopeis inserted into a lumen, for example, the inside of a small intestineor the inside of a large intestine, the fin portion of the attachmentunit comes into contact with a paries. In this state, when the rotor andthe attachment unit are rotated with respect to the insertion section,propulsive force in the directions parallel to the longitudinal axisacts on the insertion section. With the propulsive force, insertabilityof the insertion section of the endoscope in the lumen is improved.

Furthermore, in an endoscope in US2010/0069718, when a rotary gearrotates about a gear axis, an attachment unit rotates about alongitudinal axis together with a rotor.

BRIEF SUMMARY OF THE INVENTION

According to one aspect of the invention, an attachment unit which isattached to an insertion section, including an insertion main bodyextended along a longitudinal axis and configured to be inserted into alumen from an insertion opening, and which is provided to an outerperipheral direction side of the insertion section to be rotatable aboutthe longitudinal axis with respect to the insertion main body, theattachment unit includes that a tube main body which is extended alongthe longitudinal axis in a state that a gap is provided between itselfand an outer peripheral portion of the insertion section or a memberdisposed to the outer peripheral portion of the insertion section; a finportion which is spirally extended on an outer peripheral portion of thetube main body along the longitudinal axis; and a tube proximal endportion which is provided to a proximal direction side of the tube mainbody, and to which a proximal end of the attachment unit is placed, thetube proximal end portion including a proximal side gap reducing portionwhich is configured to eliminate the gap or reduce the gap as comparedwith a part to an inner peripheral direction side of the tube main bodybetween itself and the outer peripheral portion of the insertion sectionor the member disposed to the outer peripheral portion of the insertionsection, and the tube proximal end portion being configured to be placedto a distal direction side of the insertion opening in a use situationwhere the insertion section is inserted in the lumen.

Advantages of the invention will be set forth in the description whichfollows, and in part will be obvious from the description, or may belearned by practice of the invention. The advantages of the inventionmay be realized and obtained by means of the instrumentalities andcombinations particularly pointed out hereinafter.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the invention, andtogether with the general description given above and the detaileddescription of the embodiments given below, serve to explain theprinciples of the invention.

FIG. 1 is a schematic view showing an endoscope according to a firstembodiment of the present invention;

FIG. 2 is a schematic view showing a side surface of an operationsection of the endoscope according to the first embodiment on the sideopposite to that shown in FIG. 1;

FIG. 3 is a cross-sectional view schematically showing a configurationan insertion section and an attachment unit near a passive bendingportion of the endoscope according to the first embodiment;

FIG. 4 is a cross-sectional view schematically showing the configurationof the insertion section and the attachment unit near a flexible tubeconnecting portion of the endoscope according to the first embodiment;

FIG. 5 is a cross-sectional view taken along a line V-V in FIG. 4;

FIG. 6 is a cross-sectional view schematically showing a state thatexternal force in one of directions parallel to a longitudinal axis actson a fin portion of the attachment unit according to the firstembodiment;

FIG. 7 is a schematic view showing an insertion section and anattachment unit near a bending tube connecting portion of an endoscopeaccording to a first modification of the first embodiment;

FIG. 8 is a schematic view showing an insertion section and anattachment unit of an endoscope according to a second modification ofthe first embodiment;

FIG. 9A is a partially cross-sectional schematic view showing aninsertion section and an attachment unit near a first flexible portionof an endoscope according to a third modification of the firstembodiment;

FIG. 9B is a schematic view showing an operation section of an endoscopeaccording the third modification of the first embodiment;

FIG. 10 is a schematic view showing two types of attachment units thatcan be attached to an insertion section of an endoscope according to afourth modification of the first embodiment;

FIG. 11 is a schematic view showing an attachment unit of an endoscopeaccording to a fifth modification of the first embodiment;

FIG. 12 is a schematic view showing an insertion section and anattachment unit of an endoscope according to a sixth modification of thefirst embodiment;

FIG. 13 is a cross-sectional view schematically showing an attachmentunit of an endoscope according to a seventh modification of the firstembodiment;

FIG. 14 is a schematic view showing a member insertion portion in anoperation section of an endoscope according to a second embodimentaccording to the present invention;

FIG. 15 is a cross-sectional view schematically showing a state that amotor is attached to the member insertion portion in the operationsection of the endoscope according to the second embodiment;

FIG. 16 is a schematic view showing a connecting state of a gear unitand a drive unit of an endoscope according to a first modification ofthe second embodiment;

FIG. 17 is a cross-sectional view schematically showing a configurationof an insertion section and an attachment unit near a passive bendingportion of an endoscope according to a third embodiment of the presentinvention;

FIG. 18 is a cross-sectional view schematically showing theconfiguration of the insertion section and the attachment unit near aflexible tube connecting portion of the endoscope according to the thirdembodiment;

FIG. 19 is a cross-sectional view schematically showing a configurationof an insertion section and an attachment unit near a passive bendingportion of an endoscope according to a first modification of the thirdembodiment;

FIG. 20 is a schematic view showing an insertion section and anattachment unit of an endoscope according to a second modification ofthe third embodiment;

FIG. 21 is a cross-sectional view schematically showing a configurationof an insertion section and an attachment unit near a flexible tubeconnecting portion of an endoscope according to a fourth embodiment ofthe present invention;

FIG. 22 is a cross-sectional view taken along a line 22-22 in FIG. 21;

FIG. 23 is a schematic view showing a member insertion portion of anoperation section of an endoscope according to a first modification ofthe fourth embodiment; and

FIG. 24 is a cross-sectional view taken along a line 24-24 in FIG. 23.

DETAILED DESCRIPTION OF THE INVENTION First Embodiment

A first embodiment according to the present invention will now bedescribed with reference to FIG. 1 to FIG. 6. FIG. 1 is a view showingan endoscope 1 according to a first embodiment. As shown in FIG. 1, theendoscope 1 includes an insertion section 2, and an operation section 3provided to a proximal direction side of the insertion section 2. Theinsertion section 2 is configured to be inserted into a lumen such as aninside of a small intestine or an inside of a large intestine. One endof a universal cable 4 is connected to the operation section 3. A scopeconnector 5 is provided at the other end of the universal cable 4. Thescope connector 5 is connected to an image processing unit 7 such as animage processor. Further, one end of a light guide tube 8 is connectedto the scope connector 5. The other end of the light guide tube 8 isconnected to a light source unit 9.

The image processing unit 7 and the light source unit 9 are electricallyconnected to a control unit 10 such as a personal computer configured tocontrol the entire system of the endoscope 1. Furthermore, a displayunit 11 such as a monitor and an input unit 12 such as a keyboard or amouse are electrically connected to the control unit 10.

The insertion section 2 includes an elongated insertion main body 13which is extended along a longitudinal axis C. The insertion main body13 includes a distal end hard portion 15 provided on the most distaldirection side, an active bending portion 16 provided to a proximaldirection side of the distal end hard portion 15, a passive bendingportion 17 that is provided to the proximal direction side of the activebending portion 16 and configured to passively bend upon being subjectto an external force, a first flexible portion 18 provided to theproximal direction side of the passive bending portion 17, and a secondflexible portion 19 provided to the proximal direction side of the firstflexible portion 18. The active bending portion 16 is connected to thepassive bending portion 17 through a bending tube connecting portion 21.Moreover, the passive bending portion 17 is connected to the firstflexible portion 18 through an intermediate connecting portion 22.Additionally, the first flexible portion 18 is connected to the secondflexible portion 19 through a flexible tube connecting portion 23.

An attachment unit 25 is provided to an outer peripheral direction sideof the insertion section 2. The attachment unit 25 is attached to theinsertion section 2 in a state that it is rotatable about thelongitudinal axis C with respect to the insertion main body 13. Theattachment unit 25 includes a tube main body 26 extended along thelongitudinal axis C, and a fin portion 27 spirally extended along thelongitudinal axis C on an outer peripheral portion of the tube main body26. A tube distal end portion 28 is provided in the attachment unit 25from a distal end toward the proximal direction. Further, a tubeproximal end portion 29 is provided in the attachment unit 25 from aproximal end toward the distal direction.

FIG. 2 is a view showing a side surface of the operation section 3 on anopposite side of that depicted in FIG. 1. As shown in FIG. 2, a bendingoperation knob 31 which is a bending operation input section, to which abending operation of the active bending portion 16 is configured to beinput, is provided on an outer surface of the operation section 3. Inthe operation section 3, one end of a bending wire (not shown) isconnected to the bending operation knob 31. The bending wire is extendedin the insertion main body 13 (the insertion section 2) along thelongitudinal axis C, and the other end thereof is connected to a distalend of the active bending portion 16. When the bending wire is pulled bythe bending operation of the bending operation knob 31, the activebending portion 16 is bent. Further, the passive bending portion 17 isconfigured to passively bend when external force directly acts or whenexternal force indirectly acts through the active bending portion 16.For example, when external force in directions perpendicular to thelongitudinal axis C acts on the passive bending portion 17, the passivebending portion 17 bends. Furthermore, when external force in thedirections perpendicular to the longitudinal axis C acts on the activebending portion 16, the external force also acts on the passive bendingportion 17 through the active bending portion 16, and thereby thepassive bending portion 17 bends.

FIG. 3 is a view showing a configuration of the insertion section 2 andthe attachment unit 25 near the passive bending portion 17. Moreover,FIG. 4 is a view showing the configuration of the insertion section 2and the attachment unit 25 near the flexible tube connecting portion 23.As shown in FIG. 3 and FIG. 4, in the insertion main body 13 (theinsertion section 2), built-in extended members 33 such as an imagingcable, a light guide tube, and others are extended along thelongitudinal axis C. The built-in extended members 33 are extended fromthe distal end hard portion 15 provided at a distal end portion of theinsertion section 2 through the inside of the insertion main body 13(the insertion section 2) and the inside of the operation section 3.

In the distal end hard portion 15, an imaging element (not shown)configured to image a subject is provided. One end of an imaging cablewhich is one of the built-in extended members 33 is connected to theimaging element. The imaging cable (33) is connected to the imageprocessing unit 7 via the scope connector 5 through the inside of theinsertion main body 13 (the insertion section 2), the inside of theoperation section 3, and the inside of the universal cable 4. The lightguide tube which is one of the built-in extended members 33 is connectedto the light guide tube 8 by the intermediary of the scope connector 5through the inside of the insertion main body 13 (the insertion section2), the inside of the operation section 3, and the inside of theuniversal cable 4. Light exiting from the light source unit 9 is led tothe distal end hard portion 15 through the inside of the light guidetube 8 and the inside of the light guide tube which is the built-inextended member 33. Additionally, a subject is irradiated with the lightfrom an illumination window (not shown) provided on the distal end hardportion 15.

As shown in FIG. 2, a treatment instrument insertion portion 36 whichdefines a treatment instrument insertion opening 35 into which atreatment instrument such as forceps is inserted is provided on theouter surface of the operation section 3. A treatment instrument channeltube which is one of the built-in extended members 33 is connected tothe treatment instrument insertion portion 36 through the inside of theinsertion main body 13 (the insertion section 2) and the inside of theoperation section 3. As a result, the treatment instrument channel inthe treatment instrument channel tube (33) is opened in the treatmentinstrument insertion opening 35. Further, the treatment instrumentchannel is opened in an opening portion (not shown) provided on thedistal end hard portion 15. Therefore, a treatment instrument insertedfrom the treatment instrument insertion opening 35 protrudes from theopening portion of the distal end hard portion 15 toward the distaldirection through the treatment instrument channel. Furthermore, in astate that the treatment instrument protrudes from the opening portion,a treatment using the treatment instrument is given.

As shown in FIG. 3 and FIG. 4, in a range from the active bendingportion 16 to the first flexible portion 18, a protective tube 37 isprovided while covering the periphery of each built-in extended member33. A proximal end of the protective tube 37 is placed to the distaldirection side of the flexible tube connecting portion 23. When theactive bending portion 16 and the passive bending portion 17 (thebending portion) bend, the protective tube 37 is configured to protecteach built-in extended member 33 from external force that acts on thebuilt-in extended member 33. It is to be noted that covering the imagingcable and the light guide tube in the built-in extended members 33 withthe protective tubes 37 is preferable. However, the treatment instrumentchannel tube has higher strength and a greater diameter than the imagingcable and the light guide tube. Therefore, it is preferable to avoidcovering the treatment instrument channel tube with the protective tube37 and to assure a space in the insertion main body 13.

As shown in FIG. 3, first bending rings 41 made of a metal are providedto the active bending portion 16. Each first bending ring 41 is coupledwith an adjacent first bending ring 41 to allow its rotational movement.The distal end of the bending wire (not shown) is fixed to the firstbending ring (41 a) placed on the most distal direction side. When thebending wire is pulled, the first bending ring 41 rotationally moveswith respect to the first bending ring 41 adjacent thereto by externalforce, that acts in the directions perpendicular to the longitudinalaxis C, and thereby the active bending portion 16 bends.

Further, second bending rings 42 made of a metal are provided to thepassive bending portion 17. Each second bending ring 42 is coupled withan adjacent second bending ring 42 to allow its rotational movement. Awire guide configured to support the bending wire is not provided toeach second bending ring 42. The second bending ring 42 rotationallymoves with respect to the second bending ring 42 adjacent thereto byexternal force, that acts in the directions perpendicular to thelongitudinal axis C, and thereby the passive bending portion 17 bends.

A first bending ring 41 b placed on the most proximal direction side isfixed to a second bending ring 42 a placed on the most distal directionside in a fitted state. When the first bending ring 41 b is fixed to thesecond bending ring 42 a, the bending tube connecting portion 21 isformed between the active bending portion 16 and the passive bendingportion 17. In the bending tube connecting portion 21, the first bendingring 41 b is fixed to the second bending ring 42 a, and a wall thicknessof a metal portion formed of the first bending ring 41 b and the secondbending ring 42 a is increased. Therefore, the bending tube connectingportion 21 is less flexible than the active bending portion 16 and thepassive bending portion 17, and it is not bent by the external forcethat acts in the directions perpendicular to the longitudinal axis C.

A bending portion reticular tube (a bending portion blade) 43 made of ametal covers the outer peripheral direction side of the first bendingrings 41 and the second bending rings 42. A bending portion envelope 45covers the outer peripheral direction side of the bending portionreticular tube 43. The bending portion envelope 45 is made of, forexample, fluorine-containing rubber.

With the above-described configuration, the active bending portion 16functions as a first tubular portion, and the passive bending portion 17functions as a second tubular portion provided to the proximal directionside of the first tubular portion. The first tubular portion (16) andthe second tubular portion (17) bend when the external force acts in thedirections perpendicular to the longitudinal axis C. Furthermore, thebending tube connecting portion 21 serves as a first connecting tubeportion that connects the first tubular portion (16) to the secondtubular portion (17). The first connecting tube portion (21) is lessflexible than the first tubular portion (16) and the second tubularportion (17), and it is not bent by the external force in the directionsperpendicular to the longitudinal axis C.

As FIG. 3 and FIG. 4, a first helical tube (a first flex) 47 made of ametal is provided to the first flexible portion 18. A first flexibleportion reticular tube (a first flexible portion blade) 48 made of ametal covers the outer peripheral direction side of the first helicaltube 47. A first flexible portion envelope 49 covers the outerperipheral direction side of the first flexible portion reticular tube48. The first flexible portion envelope 49 is made of a material lessflexible than the bending portion envelope 45, for example, a mixedresin of polyurethane and polyester. Furthermore, bending properties ofthe first helical tube 47, when the external force acts, are reduced ascompared with that of a coupled body of the first bending rings 41 andthat of a coupled body of the second bending rings 42. Therefore, thefirst flexible portion 18 is less flexible than the active bendingportion 16 and the passive bending portion 17. However, the firstflexible portion 18 is provided with flexibility that enables bending bythe external force that acts in the directions perpendicular to thelongitudinal axis C.

The second bending ring 42 b placed on the most proximal direction sideis fixed to the first helical tube 47 and the first flexible portionreticular tube 48 in a fitted state. When the second bending ring 42 bis fixed to the first helical tube 47 and the first flexible portionreticular tube 48, an intermediate connecting portion 22 is formedbetween the passive bending portion 17 and the first flexible portion18. In the intermediate connecting portion 22, the second bending ring42 b is fixed to the first spiral tube 47 and the first flexible portionreticular tube 48, and a wall thickness of a metal portion formed of thesecond bending ring 42 b, the first helical tube 47, and the firstflexible portion reticular tube 48 is increased. Therefore, theintermediate connecting portion 22 is less flexible than the passivebending portion 17 and the first flexible portion 18, and it is not bentby the external force that acts in the directions perpendicular to thelongitudinal axis C.

Furthermore, in the intermediate connecting portion 22, a proximal endof the bending portion envelope 45 and a distal end of the firstflexible portion envelope 49 are placed. A thread 51 is wound around andan adhesive 52 covers the first flexible portion envelope 49 and thebending portion envelope 45 between the bending portion envelope 45 andthe first flexible portion envelope 49.

As shown in FIG. 4, the second flexible portion 19 has the sameconfiguration as the first flexible portion 18. Therefore, a secondhelical tube (a second flex) 53 made of a metal is provided to thesecond flexible portion 19. A second flexible portion reticular tube (asecond flexible portion blade) 55 covers the outer peripheral directionside of the second helical tube 53. A second flexible portion envelope57 covers the outer peripheral direction side of the second flexibleportion reticular tube 55. The second flexible portion envelope 57 ismade of a material less flexible than that of the bending portionenvelope 45, for example, a mixed resin of polyurethane and polyester.Moreover, the bending properties of the second helical tube 53, when theexternal force acts, are reduced as compared with that of the coupledbody of the first bending rings 41 and that of the coupled body of thesecond bending rings 42. Therefore, the second flexible portion 19 isless flexible than the active bending portion 16 and the passive bendingportion 17. However, the second flexible portion 19 has flexibility thatenables bending by the external force that acts in the directionsperpendicular to the longitudinal axis C.

A connecting mouth ring 58 made of a metal is provided to the flexibletube connecting portion 23 between the first flexible portion 18 and thesecond flexible portion 19. The connecting mouth ring 58 is fixed to thefirst helical tube 47, the first flexible portion reticular tube 48, andthe first flexible portion envelope 49 in a fitted state. Additionally,the connecting mouth ring 58 is fixed to the second helical tube 53, thesecond flexible portion reticular tube 55, and the second flexibleportion envelope 57 by fitting and with use of a fixing screw 59. A wallthickness of the connecting mouth ring 58 is greater than a wallthickness of the first helical tube 47 and a wall thickness of thesecond helical tube 53. Further, the connecting mouth ring 58 is lessflexible than the first helical tube 47 and the second helical tube 53.Therefore, the flexible tube connecting portion 23 is less flexible thanthe first flexible portion 18 and the second flexible portion 19, and itis not bent by the external force that acts in the directionsperpendicular to the longitudinal axis C.

With the above-described configuration, the first flexible portion 18functions as a third tubular portion provided to the proximal directionside of the passive bending portion 17, which is the second tubularportion, and the second flexible portion 19 serves as a fourth tubularportion provided to the proximal direction side of the third tubularportion. The third tubular portion (18) and the fourth tubular portion(19) bend when the external force acts in the directions perpendicularto the longitudinal axis C. Further, the flexible tube connectingportion 23 serves as a second connecting tube portion that connects thethird tubular portion (18) to the fourth tubular portion (19). Thesecond connecting tube portion (23) is less flexible than the thirdtubular portion (18) and the fourth tubular portion (19), and it is notbent by the external force in the directions perpendicular to thelongitudinal axis C.

As shown in FIG. 4, a rotor (a second rotor) 61 is attached to theconnecting mouth ring 58 through an elastic member 62. The rotor 61 isattached to the flexible tube connecting portion 23 (the secondconnecting tube portion) of the insertion main body 13 in a state thatit can rotate about the longitudinal axis C with respect to theinsertion main body 13 integrally with the attachment unit 25.Furthermore, water-tightness is maintained between the rotor 61 and theconnecting mouth ring 58 by the elastic member 62.

Moreover, a rotary gear 63 is attached to the connecting mouth ring 58.The rotary gear 63 is rotatable about a gear axis R. The rotary gear 63is placed on an outer peripheral portion of the connecting mouth ring 58of the insertion main body 13 and inside the rotor 61 of the insertionsection 2. That is, a gear arrangement cavity 64 where the rotary gear63 is placed is formed between the rotor 61 and the connecting mouthring 58. Here, when the water-tightness is maintained between the rotor61 and the connecting mouth ring 58 by the elastic member 62, inflow ofa liquid into the gear arrangement cavity 64 from the outside of theinsertion section 2 is avoided. Therefore, inflow of the liquid into theinsertion main body 13, where the built-in extended members 33 areprovided, is avoided.

FIG. 5 is a cross-sectional view taken along a line V-V in FIG. 4. Asshown in FIG. 5, a gear portion 65 configured to mesh with the rotarygear 63 is provided on an inner peripheral portion of the rotor 61. As aresult, the rotor 61 rotates about the longitudinal axis C in accordancewith rotation of the rotary gear 63 about the gear axis R. Moreover, therotary gear 63 and the gear portion 65 of the rotor 61 are separatedfrom the built-in extended members 33 in the insertion main body 13 bythe connecting mouth ring 58. That is, the connecting mouth ring 58functions as a partition member configured to separate the rotary gear63 and the gear portion 65 of the rotor 61 from the built-in extendedmembers 33. As a result, the rotary gear 63 and the gear portion 65 areprevented from coming into contact with the built-in extended members33.

Additionally, the proximal end of the protective tube 37, that coverseach built-in extended member 33, is placed to the distal direction sideof the flexible tube connecting portion 23, to which the rotary gear 63is disposed. That is, the proximal end of the protective tube 37 isplaced to the distal direction side of the rotary gear 63. The rotarygear 63, the rotor 61, and others as members, those are configured torotate the attachment unit 25, are disposed to the flexible tubeconnecting portion 23. Therefore, an inner diameter of the flexible tubeconnecting portion 23 (the connecting mouth ring 58) is smaller than aninner diameter of the passive bending portion 17, an inner diameter ofthe first flexible portion 18, and others. Therefore, when the proximalend of the protective tube 37, that covers each built-in extended member33, is placed to the distal direction side of the flexible tubeconnecting portion 23, a space in the flexible tube connecting portion23 is assured. It is to be noted that the first flexible portion 18 andthe second flexible portion 19 (the flexible portions) are less flexiblethan the active bending portion 16 and the passive bending portion 17(bending portions). Therefore, the external force that acts on thebuilt-in extended members 33 when bent is smaller in the flexibleportions (18, 19) than in the bending portions (16, 17). Therefore, inthe flexible portions (18, 19), the built-in extended members 33 do nothave to be covered with the protective tubes 37.

As shown in FIG. 4, a metal connection pipe 67 is attached to theconnecting mouth ring 58. A channel tube 68 is connected to theconnection pipe 67. The channel tube 68 is extended to the proximaldirection in the insertion main body 13 (the insertion section 2) alongthe longitudinal axis C. It is to be noted that the channel tube 68 is achannel tube (68) different from the treatment instrument channel tube,which is one of the built-in extended members 33.

As shown in FIG. 1, a member insertion portion (an attachment portion)72 that defines a member insertion opening 71 is provided on the outersurface of the operation section 3. The channel tube 68 is connected tothe member insertion portion 72 through the inside of the insertion mainbody 13 (the insertion section 2) and the inside of the operationsection 3. As a result, a channel 73 in the channel tube 68 is opened inthe member insertion opening 71. Further, as shown in FIG. 4, thechannel 73 is extended to the gear arrangement cavity 64 from the insideof the channel tube 68 through the inside of the connection pipe 67. Asdescribed above, the channel 73 is extended from the member insertionopening 71 on the outer surface of the operation section 3 to the geararrangement cavity 64 through the inside of the operation section 3 andthe inside of the insertion section 2. That is, the member insertionportion 72, the channel tube 68, and the connection pipe 67 constitute achannel defining portion that defines the channel 73.

As shown in FIG. 1, a motor 75 as a drive member inserted from themember insertion opening 71 is attached to the member insertion portion72. That is, the member insertion member 72 serves as an attachmentportion to which the motor 75 is attached to. One end of a motor cable76 is connected to the motor 75. The other end of the motor cable 76 isconnected to the control unit 10. The control unit 10 includes a motorcontrol section 77 configured to control rotational drive of the motor75. Furthermore, a rotating operation input switch 78 as a rotatingoperation input section that is configured to input a rotating operationof the motor 75 is provided on the outer surface of the operationsection 3. The rotating operation input switch 78 is electricallyconnected to the motor control section 77 through an electrical signalline or the like in the universal cable 4. Moreover, the rotatingoperation input switch 78 includes a first pressing portion 81, and asecond pressing portion 82 placed to the proximal direction side of thefirst pressing portion 81.

Additionally, as shown in FIG. 1 and FIG. 4, the motor 75 is connectedto the rotary gear 63 by a linear member 83 such as a wire. The linearmember 83 is extended along the channel 73. Based on the rotationaldrive of the motor 75, the linear member 83 rotates about the gear axisR, and thereby the rotary gear 63 rotates.

With the above-described configuration, when the first pressing portion81 of the rotating operation input switch 78 is pressed, the motor 75 isrotated and driven in a counterclockwise direction as seen from theproximal direction by the motor control section 77. As a result, thelinear member 83 and the rotary gear 63 rotate in the counterclockwisedirection as seen from the proximal direction. When the rotary gear 63rotates in the counterclockwise direction, the rotor 61 rotates aboutthe longitudinal axis C in a clockwise direction as seen from theproximal direction. On the other hand, when the first pressing portion81 of the rotating operation input switch 78 is pressed, the motor 75 isrotated and driven in the clockwise direction as seen from the proximaldirection by the motor control portion 77. As a result, the linearmember 83 and the rotary gear 63 rotate in the clockwise direction asseen from the proximal direction. When the rotary gear 63 rotates in theclockwise direction, the rotor 61 rotates about the longitudinal axis Cin the counterclockwise direction as seen from the proximal direction.

As shown in FIG. 4, a pulling wire 85 is fixed to the connecting mouthring 58 of the flexible connecting portion 23. Additionally, as shown inFIG. 1, a flexibility adjustment knob 87 as a flexibility adjustmentsection that is configured to change the flexibility of the secondflexible portion 19 is provided on the outer surface of the operationsection 3. The proximal end of the pulling wire 85 is connected to theflexibility adjustment knob 87 in the operation section 3. When theflexibility adjustment knob is operated, the pulling wire 85 is pulledin the proximal direction.

Additionally, as shown in FIG. 4, a coil pipe 89 through which thepulling wire 85 is inserted is provided in the second flexible portion19. A distal end of the coil pipe 89 is fixed to the pulling wire 85 bybrazing and the like. Further, the distal end of the coil pipe 89 isplaced to the proximal direction side of a proximal end of theattachment unit 25. A proximal end of the coil pipe 89 is fixed to aninner peripheral portion of the operation section 3 to the proximaldirection side of a proximal end of the second flexible portion 19. Whenthe pulling wire 85 is pulled, compression force in directions parallelto the longitudinal axis C acts on the coil pipe 89. When thecompression force acts, hardness of the coil pipe 89 is increased, andthe flexibility of the second flexible portion 19 is reduced.

As shown in FIG. 1 and FIG. 3, the tube distal end portion 28 of theattachment unit 25 is placed to the outer peripheral direction side ofthe bending tube connecting portion 21, which is the first connectingtube portion. Furthermore, as shown in FIG. 1 and FIG. 4, the tubeproximal end portion 29 of the attachment unit 25 is placed to the outerperipheral direction side of the flexible tube connecting portion 23,which is the second connecting tube portion. Moreover, the tube mainbody 26 is extended along the longitudinal axis C between the tubedistal end portion 28 and the tube proximal end portion 29. With theabove-described configuration, the attachment unit 25 is extended alongthe longitudinal axis C from the position to the outer peripheraldirection side of the bending tube connecting portion 21 to the positionto the outer peripheral direction side of the flexible tube connectingportion 23. That is, a part of the attachment unit 25 is placed to theouter peripheral direction side of the passive bending portion 17.

The tube main body 26 is made of a resin such as polyurethane. The tubemain body 26 has a gap 90 between itself and the bending portionenvelope 45 or the first flexible portion envelope 49. That is, the tubemain body 26 is provided in a state that it has the gap 90 betweenitself and the outer peripheral portion of the insertion section 2 orthe member disposed on the outer peripheral portion of the insertionsection 2 (for example, the adhesive 52).

The tube distal end portion 28 is made of a material such as rubbersofter than the tube main body 26. Therefore, as shown in FIG. 3, adistal side gap reduction portion 91, which is configured to eliminatethe gap 90 or reduce the gap 90 to be smaller than that in a part to theinner peripheral direction side of the tube main body 26, is formed onan inner peripheral portion of the tube distal end portion 28 betweenthe attachment unit 25 and the bending portion envelope 45. The gap 90is eliminated or the gap 90 is reduced to be smaller than that in a partto the inner peripheral direction side of the tube main body 26 betweenthe attachment unit 25 and the outer peripheral portion of the insertionsection 2 or the member disposed on the outer peripheral portion of theinsertion section 2 by the distal side gap reduction portion 91.Further, a coupling portion between the outer peripheral portion of thetube distal end portion 28 and the outer peripheral portion of a distalend portion of the tube main body 26 is planarly continuous without astep, a gap, and others. Furthermore, at the tube distal end portion 28and the distal end portion of the tube main body 26, an outer diameteris reduced as directing toward the distal direction. When such aconfiguration is adopted, a lumen paries can be effectively preventedfrom being sandwiched in the coupling portion between the tube distalend portion 28 and the distal end portion of the tube main body 26.

It is to be noted that, in the distal side gap reducing portion 91, aninner diameter of the tube distal end portion 28 is reduced as directingtoward the distal direction, and the gap 90 is reduced as directingtoward the distal direction. Moreover, in the distal side gap reducingportion 91, only the gap 90 is eliminated or the gap 90 is reduced ascompared with the part to the inner peripheral direction side of thetube main body 26, and water-tightness is not maintained between theattachment unit 25 and the bending portion envelope 45.

The tube proximal end portion 29 is made of a material such as rubbersofter than the tube main body 26. Therefore, as shown in FIG. 4 andFIG. 5, a proximal side gap reduction portion 92, which is configured toeliminate the gap 90 or reduce the gap 90 to be smaller than that in thepart on the inner peripheral direction side of the tube main body 26, isprovided on an inner peripheral portion of the tube proximal end portion29 between the attachment unit 25 and the connecting mouth ring 58 orthe rotor 61. The gap 90 is eliminated or the gap 90 is reduced to besmaller than that in the part on the inner peripheral direction side ofthe tube main body 26 between the attachment unit 25 and the outerperipheral portion of the insertion section 2 or the member disposed onthe outer peripheral portion of the insertion section 2 by the proximalside gap reduction portion 92. Additionally, the tube proximal endportion 29 is fixed by the proximal side gap reducing portion 29 in astate that the gap 90 is not provided in the rotor (the second rotor) 61of the insertion section 2. Therefore, when the rotor 61 rotates, theattachment unit 25 rotates integrally with the rotor 61 about thelongitudinal axis C with respect to the insertion main body 13. Further,a coupling portion between the outer peripheral portion of the tubeproximal end portion 29 and the outer peripheral portion of a proximalend portion of the tube main body 26 is planarly continuous without astep, a gap, and others. When such a configuration is adopted, a lumenparies can be effectively prevented from being sandwiched in thecoupling portion between the tube proximal end portion 29 and theproximal end portion of the tube main body 26.

It is to be noted that, in the proximal side gap reducing portion 92, aninner diameter of the tube proximal end portion 29 is reduced asdirecting toward the proximal direction, and the gap 90 is reduced asdirecting toward the proximal direction. Moreover, in the proximal sidegap reducing portion 92, only the gap 90 is eliminated or the gap 90 isreduced as compared with the part to the inner peripheral direction sideof the tube main body 26, and water-tightness is not maintained betweenthe attachment unit 25 and the connecting mouth ring 58 or the rotor 61.

The fin portion 27 extended on the outer peripheral portion of the tubemain body 26 is made of rubber or the like. The fin portion 27 is fixedto the tube main body 26 by adhesion or welding. As shown in FIG. 1, thefin portion 27 is extended in the spiral form in the clockwise directionas seen from the proximal direction. Additionally, the fin portion 27 isextended in a state that an acute angle α with respect to thelongitudinal axis C becomes greater than 45°. When the insertion section2 of the endoscope 1 is inserted into the lumen such as an inside of asmall intestine or an inside of a large intestine, the fin portion 27 ofthe attachment unit 25 comes into contact with a paries. In this state,the rotor 61 and the attachment unit 25 are rotated about thelongitudinal axis C with respect to the insertion main body 13. As aresult, propulsive force in one of the directions parallel to thelongitudinal axis C acts on the insertion section 2.

In this embodiment, the fin portion 27 is extended in the spiral form inthe clockwise direction as seen from the proximal direction. Therefore,when the rotor 61 and the attachment unit 25 rotate in the clockwisedirection as seen from the proximal direction, the propulsive forcetoward the distal direction acts on the insertion section 2. As aresult, insertability of the insertion section 2 in the lumen can beimproved. On the other hand, when the rotor 61 and the attachment unit25 rotate in the counterclockwise direction as seen from the proximaldirection, the propulsive force toward the proximal direction acts onthe insertion section 2. As a result, removability of the insertionsection 2 in the lumen can be improved.

It is to be noted that, in this embodiment, when the first pressingportion 81 of the rotating operation input switch 78 is pressed, therotor 61 rotates in the clockwise direction. Furthermore, when thesecond pressing portion 82 is pressed, the rotor 61 rotates in thecounterclockwise direction. That is, the propulsive force toward thedistal direction is exerted when the first pressing portion 81 ispressed, and the propulsive force toward the proximal direction isexerted when the second pressing portion 82 placed to the proximaldirection side of the first pressing portion 81 is pressed. Therefore,an operator can readily perform operations by using the rotatingoperation input switch 78.

Additionally, the fin portion 27 may be extended in the spiral shape inthe counterclockwise direction as seen from the proximal direction. Inthis case, when the rotor 61 and the attachment unit 25 rotate in theclockwise direction as seen from the proximal direction, the propulsiveforce toward the proximal direction acts on the insertion section 2. Onthe other hand, when the rotor 61 and the attachment unit 25 rotate inthe counterclockwise direction as seen from the proximal direction, thepropulsive force toward the distal direction acts on the insertionsection 2. However, when the insertion section 2 is inserted into thelarge intestine, it is preferable for the fin portion 27 to be spirallyformed in the clockwise direction as seen from the proximal direction interms of a relationship with a shape of the large intestine and others,like this embodiment.

As shown in FIG. 3 and FIG. 4, the fin portion 27 includes a first widthdimension portion 93 to which the outer peripheral end is placed in astate that the external force is not exerted in the directions parallelto the longitudinal axis C. In the state that the external force is notexerted in the directions parallel to the longitudinal axis C, the firstwidth dimension portion 93 has a first width dimension T1 in thedirections parallel to the longitudinal axis C. Further, a second widthdimension portion 95 is provided to the inner peripheral direction sideof the first width dimension portion 93. In the state that the externalforce is not exerted in the directions parallel to the longitudinal axisC, the second width dimension portion 95 has a second width dimension T2smaller than the first width dimension T1 in the directions parallel tothe longitudinal axis C. In the state that the external force is notexerted in the directions parallel to the longitudinal axis C, the outerperipheral end of the fin portion 27 placed at the first width dimensionportion 93 comes into contact with the paries. Furthermore, in the statethat the external force is not exerted in the directions parallel to thelongitudinal axis C, a dimension from the longitudinal axis C to theouter peripheral end of the fin portion 27 is D1.

FIG. 6 is a view showing a state that the external force in one of thedirections parallel to the longitudinal axis C acts on the fin portion27. As shown in FIG. 6, when the external force is exerted in one of thedirections parallel to the longitudinal axis C, the second widthdimension portion 95 bends. As a result, the dimension from thelongitudinal axis C to the outer peripheral end of the fin portion 27 isD2, and it is smaller than dimension D1 in the state that the externalforce is not exerted in the directions parallel to the longitudinal axisC. That is, the dimension from the longitudinal axis C to the outerperipheral end of the fin portion 27 (D1 or D2) varies in accordancewith the state of exertion of the external force in the directionsparallel to the longitudinal axis C. Here, dimension D1 is preferablygreater than 10 mm, and dimension D2 is preferably equal to or smallerthan 10 mm.

It is to be noted that, when the attachment unit 25 is rotated in thestate that fin portion 27 is in contact with the paries, the externalforce around the longitudinal axis C acts on the fin portion 27.However, as described above, in this embodiment, the fin portion 27 isextended in a state that the acute angle α with respect to thelongitudinal axis C becomes greater than 45°. Therefore, the secondwidth dimension portion 95 hardly bends with respect to the externalforce around the longitudinal axis C. Moreover, since the acute angle αof the fin portion 27 with respect to the longitudinal axis C is greaterthan 45°, the second width dimension portion 95 is apt to bend withrespect to the external force in the directions parallel to thelongitudinal axis C. Therefore, the second width dimension portion 95bends, even if the external force in one of the directions parallel tothe longitudinal axis C that acts on the fin portion 27 is smallexternal force that is not greater than 10 N.

Additionally, in a cross section parallel to the longitudinal axis C,the first width dimension portion 93 is formed into a substantiallycircular shape, but the present invention is not restricted thereto. Forexample, in the cross section parallel to the longitudinal axis C, thefirst width dimension portion 93 may be formed into a substantiallysquare shape. That is, in the state that the external force is notexerted in the directions parallel to the longitudinal axis C, it issatisfactory for the second width dimension T2 of the second widthdimension portion 95 to be smaller than the first width dimension T1 ofthe first width dimension portion 93.

Further, as shown in FIG. 1, the input unit 12 includes a rotationalspeed input section 96 configured to input a rotational speed of theattachment unit 25. The motor control section 77 is configured tocontrol a rotational speed of the motor 75 based on an input in therotational speed input section 96, and thereby configured to control therotational speed of the attachment unit 25. Furthermore, the controlunit 10 includes a notification processing section 97 configured toprocess notifying an operator of a state that the attachment unit 25 isrotated. Based on the processing in the notification processing section97, the operator can recognize the state that the attachment unit 25 isrotated by display in the display unit 11, generation of sound, andothers.

Moreover, the image processing unit 7 includes brightness detectionsection 98 configured to detect brightness of an image of a subject. Thecontrol unit 10 includes a directional relationship detection section 99configured to detect a relationship between an insertion direction ofthe insertion section 2 and an extending direction of the lumen based ona detection result in the brightness detection section 98. The motorcontrol section 77 is configured to control rotational drive of themotor 75 based on a detection result in the directional relationshipdetection section 99. In an image of the subject, a lumen part is dark,and a paries part is bright. Therefore, when the insertion direction ofthe insertion section 2 substantially coincides with the extendingdirection of the lumen, a central part of the image of the subject isdark. In this situation, the directional relationship detection section99 determines that the insertion direction of the insertion section 2substantially coincides with the extending direction of the lumen, andthe motor 75 is rotated and driven by the motor control section 77. As aresult, the attachment unit 25 rotates. On the other hand, when theinsertion direction of the insertion section 2 is greatly different fromthe extending direction of the lumen in, for example, a state that thedistal end of the insertion section 2 faces the paries, the central partof the image of the subject is bright. In this situation, thedirectional relationship detection section 99 determines that theinsertion direction of the insertion section 2 is greatly different fromthe extending direction of the lumen, and the motor 75 is not rotatedand driven by the motor control section 77. Therefore, the attachmentunit 25 does not rotate.

A function of the endoscope 1 according to this embodiment will now bedescribed. The insertion section 2 of the endoscope 1 is inserted intothe lumen from the mouth or the anus, and it is removed from the lumenthrough the mouth or the anus. When inserting the insertion section 2into the small intestine or the large intestine, and when the removingthe insertion section 2 from the small intestine or the large intestine,the insertion section 2 passes through the esophagus or the anus havingan inner diameter of 20 mm or below. On the other hand, each of thesmall intestine and the large intestine has an inner diameter greaterthan 20 mm.

Like the endoscope according to this embodiment, as endoscopes eachincluding an attachment unit which is provided with a tube main body anda fin portion, there are endoscopes disclosed in US2010/0076264 andUS2010/0069718. In each of these endoscopes, a dimension from alongitudinal axis to an outer peripheral end of a fin portion does notchange in response to a change in the state of exertion of the externalforce in the directions parallel to the longitudinal axis. Therefore,when the dimension from the longitudinal axis to the outer peripheralend of the fin portion is greater than 10 mm, the insertion section hasa difficulty in passing through the lumen with a small inner diameter,for example, the esophagus or the anus. On the other hand, when thedimension from the longitudinal axis to the outer peripheral end of thefin portion is not greater than 10 mm, the fin portion does not comeinto contact with the paries in the lumen with a large inner diameter,for example, the small intestine or the large intestine. Therefore, evenwhen the attachment unit is rotated, the propulsive force is notgenerated in one of the directions parallel to the longitudinal axis.

On the other hand, in the endoscope 1 according to this embodiment, thedimension (D1 or D2) from the longitudinal axis C to the outerperipheral end of the fin portion 27 changes in response to the state ofexertion of the external force in the directions parallel to thelongitudinal axis C. When inserting or removing the insertion section 2into or from the lumen in the state that the attachment unit 25 is notrotated, force of 2N to 20N is applied in one of the directions parallelto the longitudinal axis C by an operator. Therefore, when the insertionsection 2 passes through the lumen having a small inner diameter, theexternal force of 2N to 20N in one of the directions parallel to thelongitudinal axis C is exerted with respect to the fin portion 27 fromthe paries. The second width dimension portion 95 of the fin portion 27bends by the external force from the paries. As a result, the dimensionfrom the longitudinal axis C to the outer peripheral end of the finportion 27 becomes dimension D2 that is not greater than 10 mm.Therefore, the insertion section 2 can readily pass through the lumenhaving a small inner diameter.

Furthermore, when the insertion section 2 passes through the lumenhaving a large inner diameter, the external force in the directionsparallel to the longitudinal axis C is not exerted from the paries withrespect to the fin portion 27. Therefore, the second width dimensionportion 95 of the fin portion 27 does not bend, and the dimension fromthe longitudinal axis C to the outer peripheral end of the fin portion27 becomes dimension D1 greater than 10 mm. At this time, the firstwidth dimension portion 93 of the fin portion 27 comes into contact withthe paries. When the attachment unit 25 is rotated in this state, thepropulsive force in one of the directions parallel to the longitudinalaxis C is exerted with respect to the insertion section 2. With thepropulsive force, when passing through the lumen having a large innerdiameter, the insertability and the removability of the insertionsection 2 can be improved. As described above, in the endoscope 1according to this embodiment, the insertion section 2 is inserted orremoved in accordance with the inner diameter of the lumen at a partthrough which the insertion section 2 passes.

Further, in the fin portion 27 in a state that the external force is notexerted in the directions parallel to the longitudinal axis C, the firstwidth dimension T1 of the first width dimension portion 93 is greaterthan the second width dimension T2 of the second width dimension portion95. Therefore, a contact area of the fin portion 27 and the paries isincreased. Therefore, when the attachment unit 25 rotates, thepropulsive force in one of the directions parallel to the longitudinalaxis C is further increased. As a result, the insertability and theremovability of the insertion section 2 when passing through the lumenhaving a large inner diameter are further improved.

Furthermore, when the insertion section 2 passes through the lumenhaving a large inner diameter, since the rotor 61 and the attachmentunit 25 rotate in the clockwise direction as seen from the proximaldirection, the propulsive force in the distal direction acts on theinsertion section 2. As a result, the insertability of the insertionsection 2 in the lumen can be improved. On the other hand, when therotor 61 and the attachment unit 25 rotate in the counterclockwisedirection as seen from the proximal direction, the propulsive forcetoward the proximal direction acts on the insertion section 2. As aresult, the removability of the insertion section 2 in the lumen isimproved.

Here, in the endoscopes disclosed in US2010/0076264 and US2010/0069718,at each of distal ends and proximal ends of attachment units, a gap isprovided between the attachment unit and an outer peripheral portion ofan insertion section. Therefore, when the attachment unit is rotatedwith respect to the insertion section, the paries may be possiblysandwiched between the attachment unit and the outer peripheral portionof the insertion section. When the paries is sandwiched between theattachment unit and the outer peripheral part of the insertion section,the insertability and the removability of the insertion section arereduced, and a burden on a patient is increased.

On the other hand, in this embodiment, since the tube distal end portion28 of the attachment unit 25 is made of a material softer than the tubemain body 26, the distal side gap reduction portion 91 is formed on theinner peripheral portion of the tube distal end portion 28. The distalside gap reduction portion 91 eliminates the gap 90 between theattachment unit 25 and the outer peripheral part of the insertionsection 2 or the member disposed on the outer peripheral portion of theinsertion section 2, or reduces the gap 90 to be smaller than the partto the inner peripheral direction side of the tube main body 26.Therefore, when the propulsive force toward the distal direction isexerted with respect to the insertion section 2 due to the rotation ofthe attachment unit 25 in the clockwise direction, the paries can beeffectively prevented from being sandwiched between the tube distal endportion 28 and the outer peripheral portion of the insertion section 2.

Moreover, since the tube proximal end portion 29 is made of a materialsofter than the tube main body 26, the proximal side gap reductionportion 92 is formed on the inner peripheral portion of the tubeproximal end portion 29. The tube proximal end portion 29 is fixed tothe rotor (the second rotor) 61 of the insertion section 2 without thegap 90 by the proximal side gap reduction portion 92. That is, theproximal side gap reduction portion 92 eliminates the gap 90 between theattachment unit 25 and the outer peripheral portion of the insertionsection 2 or the member disposed on the outer peripheral portion of theinsertion section 2, or reduces the gap 90 to be smaller than the partto the inner peripheral direction side of the tube main body 26.Therefore, when the propulsive force toward the proximal direction isexerted with respect to the insertion section 2 due to the rotation ofthe attachment unit 25 in the counterclockwise direction, the paries canbe effectively prevented from being sandwiched between the tube proximalend portion 29 and the outer peripheral portion of the insertion section2. As described above, it is possible to effectively avoid sandwichingthe paries between the attachment unit 25 and the outer peripheralportion of the insertion section 2.

Additionally, the tube main body 26 of the attachment unit 25 isprovided with the gap 90 between itself and the outer peripheral portionof the insertion section 2 or the member disposed on the outerperipheral portion of the insertion section 2 (for example, the adhesive52). Therefore, rotation properties of the attachment unit 25 withrespect to the insertion main body 13 are improved. Accordingly, whenthe attachment unit 25 rotates, the propulsive force in one of thedirections parallel to the longitudinal axis C is further increased. Asa result, when passing through the lumen having a large inner diameter,the insertability and the removability of the insertion section 2 arefurther enhanced.

Further, in the endoscope 1, the tube distal end portion 28 is placed tothe outer peripheral direction side of the bending tube connectingportion (the first connecting tube portion) 21 that connects the activebending portion (the first tubular portion 16) to the passive bendingportion (the second tubular portion 17). The bending tube connectingportion 21 is less flexible than the active bending portion 16 and thepassive bending portion 17, and it is not bent by the external force inthe directions perpendicular to the longitudinal axis C. Therefore, evenwhen the active bending portion 16 and the passive bending portion 17bend, the gap 90 is hardly increased between the tube distal end portion28 and the outer peripheral portion of the insertion section 2 or themember disposed on the outer peripheral portion of the insertion section2. Therefore, the paries can be further effectively prevented from beingsandwiched between the tube distal end portion 28 and the outerperipheral portion of the insertion section 2.

Further, the tube proximal end portion 29 is placed to the outerperipheral direction side of the flexible tube connecting portion (thesecond connecting tube portion) 23 that connects the first flexibleportion (the third tubular portion) 18 to the second flexible portion(the fourth tubular portion) 19. The flexible tube connecting portion 23is less flexible than the first flexible portion 18 and the secondflexible portion 19, and it is not bent by the external force in thedirections perpendicular to the longitudinal axis C. Therefore, evenwhen the first flexible portion 18 and the second flexible portion 19bend, the gap 90 is hardly increased between the tube proximal endportion 29 and the outer peripheral portion of the insertion section 2or the member disposed on the outer peripheral portion of the insertionsection 2. Therefore, the paries is further effectively prevented frombeing sandwiched between the tube proximal end portion 29 and the outerperipheral portion of the insertion section 2.

Further, in the small intestine or the large intestine, there are partswhere the lumen bends. Therefore, the insertion section (2) must haveflexibility to some extent to facilitate passage through the bent partsof the lumen. In each of the endoscopes disclosed in US2010/0076264 andUS2010/0069718, the attachment unit is extended over the substantiallyentire length of the insertion section in the directions parallel to thelongitudinal axis. In general, the part on the proximal direction sideof the insertion section of the endoscope is the flexible portion. Asdescribed above, the flexible portion is less flexible than the passivebending portion that is passively bent by the external force. Therefore,since the attachment unit is placed to the outer peripheral directionside of the flexible portion, the flexibility of the flexible portion isreduced. When the flexibility of the flexible portion is decreased, theinsertion section has a difficult in passing through bent parts of thelumen, and the insertability and the removability of the insertionsection in the lumen are reduced.

Here, it is possible to consider avoiding a reduction in flexibility ofthe part on the proximal direction side of the insertion section byextending the passive bending portion to the proximal end of theinsertion section to the proximal direction side of the active bendingportion without providing the flexible portion to the insertion section.However, in the state that the attachment unit is not rotated, theinsertion section is inserted or removed in the lumen by the force inone of the directions parallel to the longitudinal axis applied by anoperator. Therefore, with the configuration that the flexibility of theinsertion section is reduced as going toward the proximal direction,transmissibility of the force applied by the operator is held.Therefore, in the configuration that the passive bending portion isextended to the proximal end, the flexibility of the part on theproximal direction side of the insertion section is extremely increased.Therefore, in the state that the attachment unit is not rotated, wheninserting or removing the insertion section, the transmissibility of theforce applied by the operator is reduced.

On the other hand, in this embodiment, the passive bending portion 17 isplaced to the proximal direction side of the active bending portion 16,and the first flexible portion 18 and the second flexible portion 19,each being less flexible than the passive bending portion 17, are placedto the proximal direction side of the passive bending portion 17.Further, the attachment unit 25 is extended along the longitudinal axisC from the position to the outer peripheral direction side of thebending tube connecting portion 21 to the position to the outerperipheral direction side of the flexible tube connecting portion 23.That is, a part of the attachment unit 25 is placed to the outerperipheral direction side of the passive bending portion 17. With theabove-described configuration, the attachment unit 25 is not placed tothe outer peripheral direction side of the second flexible portion 19provided at the part on the proximal direction side of the insertionsection 2. Therefore, a reduction in flexibility of the second flexibleportion 19 is avoided. Therefore, the insertion section 2 can readilypass through the bent parts of the lumen, and the insertability and theremovability of the insertion section 2 in the lumen can be improved.

Additionally, in the insertion section 2, the first flexible portion 18and the second flexible portion 19 are provided to the proximaldirection side of the passive bending portion 17. Therefore, theflexibility in the part on the proximal direction side of the insertionsection 2 is not extremely increased. Therefore, when inserting orremoving the insertion section 2 in the state that the attachment unit25 is not rotated, the force in one of the directions parallel to thelongitudinal axis C applied by the operator is appropriatelytransmitted.

Here, in the state that the attachment unit 25 is attached to theinsertion section 2, the flexibility of the second flexible tube portion19 is greater than that of the first flexible tube portion 18. Asdescribed above, in the state that the attachment unit 25 is notrotated, it is preferable for the flexibility of the insertion sectionto be reduced as going toward the proximal direction. Therefore, in thisembodiment, the pulling wire 85 and the coil pipe 89 are provided in thesecond flexible portion 19. When the pulling wire 85 is pulled, thecompression force in the directions parallel to the longitudinal axis Cacts on the coil pipe 89. When the compression force acts, the hardnessof the coil pipe 89 is increased, and the flexibility of the secondflexible portion 19 is reduced. Since the flexibility of the secondflexible portion 19 is reduced, when inserting or removing the insertionsection 2 in the state that the attachment unit 25 is not rotated, thetransmissibility of the force in the directions parallel to thelongitudinal axis C applied by the operator is further improved.

Therefore, the endoscope 1 having the above-described configurationexerts the following effects. That is, in the endoscope 1 according tothis embodiment, since the tube distal end portion 28 of the attachmentunit 25 is made of a material softer than the tube main body 26, thedistal side gap reduction portion 91 is formed on the inner peripheralportion of the tube distal end portion 28. The distal side gap reductionportion 91 eliminates the gap 90 between the attachment unit 25 and theouter peripheral portion of the insertion section 2 or the memberdisposed on the outer peripheral portion of the insertion section 2, orreduces the gap 90 to be smaller than the part to the inner peripheraldirection side of the tube main body 26. Therefore, when the propulsiveforce toward the distal direction acts on the insertion section 2 due tothe rotation of the attachment unit 25 in the clockwise direction, theparies can be effectively prevented from being sandwiched between thetube distal end portion 28 and the outer peripheral portion of theinsertion section 2.

Additionally, since the tube proximal end portion 29 is made of amaterial softer than the tube main body 26, the proximal side gapreduction portion 92 is formed on the inner peripheral portion of thetube proximal end portion 29. The tube proximal end portion 29 is fixedto the rotor (the second rotor) 61 of the insertion section 2 withoutthe gap 90 by the proximal side gap reduction portion 92. That is, theproximal side gap reduction portion 92 eliminates the gap 90 between theattachment unit 25 and the outer peripheral portion of the insertionsection 2 or the member disposed on the outer peripheral portion of theinsertion section 2, or reduces the gap 90 to be smaller than the partto the inner peripheral direction side of the tube main body 26.Therefore, when the propulsive force in the proximal direction acts onthe insertion section 2 due to the rotation of the attachment unit 25 inthe counterclockwise direction, the paries can be effectively preventedfrom being sandwiched between the tube proximal end portion 29 and theouter peripheral portion of the insertion section 2. As described above,in the endoscope 1, it is possible to effectively avoid sandwiching theparies between the attachment unit 25 and the outer peripheral portionof the insertion section 2.

Furthermore, in the endoscope 1, the tube main body 26 of the attachmentunit 25 is provided with the gap 90 between itself and the outerperipheral portion of the insertion section 2 or the member disposed onthe outer peripheral portion of the insertion section 2. Therefore, therotation properties of the attachment unit 25 with respect to theinsertion main body 13 can be improved. Therefore, when the attachmentunit 25 rotates, the propulsive force in one of the directions parallelto the longitudinal axis C is increased. Therefore, when passing throughthe lumen having a large inner diameter, the insertability and theremovability of the insertion section 2 can be improved.

Moreover, in the endoscope 1, the tube distal end portion 28 is placedto the outer peripheral direction side of the bending tube connectingportion (the first connecting tube portion) 21 that connects the activebending portion (the first tubular portion) 16 with the passive bendingportion (the second tubular portion) 17. The bending tube connectingportion 21 is less flexible than the active bending portion 16 and thepassive bending portion 17, and it is not bent by the external force inthe directions perpendicular to the longitudinal axis C. Therefore, evenwhen the active bending portion 16 and the passive bending portion 17bend, the gap 90 is hardly increased between the tube distal end portion28 and the outer peripheral portion of the insertion section 2 or themember disposed on the outer peripheral portion of the insertion section2. Therefore, the paries can be further effectively prevented from beingsandwiched between the tube distal end portion 28 and the outerperipheral portion of the insertion section 2.

Additionally, in the endoscope 1, the tube proximal end portion 29 isplaced to the outer peripheral direction side of the flexible tubeconnecting portion (the second connecting tube portion) 23 that connectsthe first flexible portion (the third tubular portion) 18 to the secondflexible portion (the fourth tubular portion) 19. The flexible tubeconnecting portion 23 is less flexible than the first flexible portion18 and the second flexible portion 19, and it is not bent by theexternal force in the directions perpendicular to the longitudinal axisC. Therefore, even when the first flexible portion 18 and the secondflexible portion 19 bend, the gap 90 is hardly increased between thetube proximal end portion 29 and the outer peripheral portion of theinsertion section 2 and the member disposed on the outer peripheralportion of the insertion section 2. Therefore, the paries can be furthereffectively prevented from being sandwiched between the tube proximalend portion 29 and the outer peripheral portion of the insertion section2.

Further, in the endoscope 1, the dimension (D1 or D2) from thelongitudinal axis C to the outer peripheral end of the fin portion 27varies in accordance with the state of exertion of the external force inthe directions parallel to the longitudinal axis C. In the state thatthe attachment unit 25 is not rotated, when inserting or removing theinsertion section 2 into or from the lumen, the operator applies theforce in one of the directions parallel to the longitudinal axis C.Therefore, when the insertion section 2 passes through the lumen havinga small inner diameter, the external force in one of the directionsparallel to the longitudinal axis C acts on the fin portion 27 from theparies. The second width dimension portion 95 of the fin portion 27bends by the external force from the paries. As a result, the dimensionfrom the longitudinal axis C to the outer peripheral end of the finportion 27 is reduced to dimension D2. Therefore, the insertion section2 can readily pass through the lumen having the small inner diameter.

Furthermore, in the endoscope 1, when the insertion section 2 passesthrough the lumen having a large inner diameter, the external force inthe directions parallel to the longitudinal axis C is not exerted withrespect to the fin portion 27. Therefore, the second width dimensionportion 95 of the fin portion 27 does not bend, and the dimension fromthe longitudinal axis C to the outer peripheral end of the fin portion27 is dimension D1 greater than dimension D2. At this time, the firstwidth dimension portion 93 of the fin portion 27 comes into contact withthe paries. When the attachment unit 25 rotates in this state, thepropulsive force in one of the directions parallel to the longitudinalaxis C acts on the insertion section 2. With the propulsive force, whenpassing through the lumen having the large inner diameter, theinsertability and the removability of the insertion section 2 can beimproved. As described above, in the endoscope 1, the insertion section2 can be inserted or removed in accordance with the inner diameter ofthe lumen at a part through which the insertion section 2 passes.

Moreover, in the endoscope 1, in the state that the external force doesnot act on the fin portion 27 in the directions parallel to thelongitudinal axis C, the first width dimension T1 of the first widthdimension portion 93 is greater than the second width dimension T2 ofthe second width dimension portion 95. Therefore, a contact area of thefin portion 27 and the paries is increased. Therefore, when theattachment unit 25 rotates, the propulsive force in one of thedirections parallel to the longitudinal axis C is further increased. Asa result, it is possible to further improve the insertability and theremovability of the insertion section 2 when passing through the lumenhaving the large inner diameter.

Additionally, in the endoscope 1, the passive bending portion 17 isplaced to the proximal direction side of the active bending portion 16,and the first flexible portion 18 and the second flexible portion 19,having the flexibilities lower than that of the passive bending portion17, are placed to the proximal direction side of the passive bendingportion 17. Further, the attachment unit 25 is extended from theposition to the outer peripheral direction side of the bending tubeconnecting portion 21 to the position to the outer peripheral directionside of the flexible tube connecting portion 23 along the longitudinalaxis C. That is, a part of the attachment unit 25 is placed to the outerperipheral direction side of the passive bending portion 17. With theabove-described configuration, the attachment unit 25 is not placed tothe outer peripheral direction side of the second flexible portion 19provided in the region on the proximal direction side of the insertionsection 2. Accordingly, a reduction in flexibility of the secondflexible portion 19 is avoided. Therefore, the insertion section 2 caneasily pass through the bent parts of the lumen, and the insertabilityand the removability of the insertion section 2 in the lumen can beimproved.

Further, in the endoscope 1, the first flexible portion 18 and thesecond flexible portion 19 are provided to the proximal direction sideof the passive bending portion 17. Therefore, the flexibility in theregion on the proximal direction side of the insertion section 2 is notextremely increased. Therefore, when inserting or removing the insertionsection 2 in the state that the attachment unit 25 is not rotated, theforce in one of the directions parallel to the longitudinal axis Capplied by the operator can be appropriately transmitted.

Furthermore, in the endoscope 1, the pulling wire 85 and the coil pipe89 are provided in the second flexible portion 19. When the pulling wire85 is pulled, the compression force in the directions parallel to thelongitudinal axis C acts on the coil pipe 89. When the compression forceacts, the hardness of the coil pipe 89 is increased, and the flexibilityof the second flexible portion 19 is reduced. Since the flexibility ofthe second flexible portion 19 is reduced, when inserting or removingthe insertion section 2 in the state that the attachment unit 25 is notrotated, the transmissibility of the force in one of the directionsparallel to the longitudinal axis C applied by the operator can befurther improved.

Moreover, in the endoscope 1, the rotary gear 63 and the gear portion 65of the rotor 61 are separated from the built-in extended members 33 inthe insertion main body 13 by the connecting mouth ring (the partitionmember) 58 provided in the flexible tube connecting portion 23. As aresult, the rotary gear 63 and the gear portion 65 can be effectivelyprevented from coming into contact with the built-in extended members33.

Additionally, in the endoscope 1, the water-tightness is maintainedbetween the rotor 61 and the connecting mouth ring 58 by the elasticmember 62. As a result, inflow of a liquid into the gear arrangementcavity 64 from the outside of the insertion section 2 is avoided.Therefore, inflow of the liquid into the insertion main body 13, wherethe built-in extended members 33 are provided, is avoided.

Further, in the endoscope 1, the proximal end of the protective tube 37,that covers each built-in extended member 33, is placed to the distaldirection side of the flexible tube connecting portion 23 to which therotary gear 63 is disposed. That is, the proximal end of the protectivetube 37 is placed to the distal direction side of the rotary gear 63.The rotary gear 63, the rotor 61, and others as members that rotate theattachment unit 25 are attached to the flexible tube connecting portion23. Therefore, an inner diameter of the flexible tube connecting portion23 (the connecting mouth ring 58) is smaller than an inner diameter ofthe passive bending portion 17, an inner diameter of the first flexibleportion 18, and others. Therefore, when the proximal end of theprotective tube 37, that covers each built-in extended member 33, isplaced to the distal direction side of the flexible tube connectingportion 23, a space in the flexible tube connecting portion 23 isassured.

(Modification of First Embodiment)

It is to be noted that, in the first embodiment, the insertion section 2includes the rotor (the second rotor) 61 to which the tube proximal endportion 29 is fixed without a gap. However, as a first modification, asshown in FIG. 7, the insertion section 2 may include a rotor (a firstrotor) 101 to which the tube distal end portion 28 is fixed without agap. The rotor 101 can rotate about the longitudinal axis C with respectto the insertion main body 13. The principle of rotating the rotor 101is the same as that of the rotor 61, and hence a description thereofwill be omitted. The tube distal end portion 28 is fixed to the rotor(the first rotor) 101 of the insertion section 2 without the gap 90 bythe distal side gap reduction portion 91 of the tube distal end portion28.

Further, in this modification, the rotor 101 is provided to the bendingtube connecting portion 21. Therefore, the tube distal end portion 28 isplaced to the outer peripheral direction side of the bending tubeconnecting portion (the first connecting tube portion) 21 that connectsthe active bending portion (the first tubular portion) 16 to the passivebending portion (the second tubular portion) 17. The bending tubeconnecting portion 21 is less flexible than the active bending portion16 and the passive bending portion 17, and it is not bent by theexternal force in the directions perpendicular to the longitudinal axisC. Therefore, in this modification, likewise, when the active bendingportion 16 and the passive bending portion 17 bend, the gap 90 is hardlyincreased between the tube distal end portion 28 and the outerperipheral portion of the insertion section 2 or the member disposed onthe outer peripheral portion of the insertion section 2.

Further, both rotor (the first rotor) 101 and the rotor (the secondrotor) 61 may be provided. Therefore, providing at least one of therotor (the first rotor) 101 and the rotor (the second rotor) 61 cansuffice.

Furthermore, in the first embodiment, the attachment unit 25 is extendedfrom the position to the outer peripheral direction side of the bendingtube connecting portion 21 to the position to the outer peripheraldirection side of the flexible tube connecting portion 23 along thelongitudinal axis C. However, as a second modification, as shown in FIG.8, the attachment unit 25 may be extended from a position to the outerperipheral direction side of a bending tube connecting portion 21 to aposition to the outer peripheral direction side of an intermediateconnecting portion 22A along the longitudinal axis C. In thismodification, the insertion main body 13 includes an active bendingportion 16A, a passive bending portion 17A provided to the proximaldirection side of the active bending portion 16A, and a flexible portion18A provided to the proximal direction side of the passive bendingportion 17A. The active bending portion 16A is connected to the passivebending portion 17A through the bending tube connecting portion 21A. Thepassive bending portion 17A is connected to the flexible portion 18Athrough the intermediate connecting portion 22A. The flexible portion18A is extended to a proximal end of the insertion section 2 along thelongitudinal axis C.

Here, the configuration of the active bending portion 16A issubstantially the same as the active bending portion 16 according to thefirst embodiment, the configuration of the passive bending portion 17Ais substantially the same as the passive bending portion 17 according tothe first embodiment, and the configuration of the flexible portion 18Ais substantially the same as the first flexible portion 18 according tothe first embodiment. Moreover, the configuration of the bending tubeconnecting portion 21A is substantially the same as the bending tubeconnecting portion 21 according to the first embodiment, and theconfiguration of the intermediate connecting portion 22A issubstantially the same as the intermediate connecting portion 22according to the first embodiment. Therefore, a description on theconfigurations of the active bending portion 16A, the passive bendingportion 17A, the flexible portion 18A, the bending tube connectingportion 21A, and the intermediate connecting portion 22A will beomitted.

In this modification, the active bending portion 16A functions as afirst tubular portion, and the passive bending portion 17A functions asa continuous body of a second tubular portion and a third tubularportion. Furthermore, the flexible portion 18A serves as a fourthtubular portion. Moreover, the bending tube connecting portion 21Aserves as a first connecting tube portion that connects the firsttubular portion (16A) with the second tubular portion (17A). Moreover,the intermediate connecting portion 22A serves as a second connectingtube portion that connects the third tubular portion (17A) with thefourth tubular portion (18A).

In this modification, the tube distal end portion 28 is placed to theouter peripheral direction side of the bending tube connecting portion(the first connecting tube portion) 21A that connects the active bendingportion (the first tubular portion) 16A to the passive bending portion(the second tubular portion) 17A. The bending tube connecting portion21A is less flexible than the active bending portion 16A and the passivebending portion 17A, and it is not bent by the external force in thedirections perpendicular to the longitudinal axis C. Therefore, in thismodification, likewise, when the active bending portion 16A and thepassive bending portion 17A bend, the gap 90 is hardly increased betweenthe tube distal end portion 28 and the outer peripheral portion of theinsertion section 2 or the member disposed on the outer peripheralportion of the insertion section 2.

Furthermore, the tube proximal end portion 29 is placed to the outerperipheral direction side of the intermediate connecting portion (thesecond connecting tube portion) 22A that connects the passive bendingportion (the third tubular portion) 17A to the flexible portion (thefourth tubular portion) 18A. The intermediate connecting portion 22A isless flexible than the passive bending portion 17A and the flexibleportion 18A, and it is not bent by the external force in the directionsperpendicular to the longitudinal axis C. Therefore, in thismodification, likewise, when the passive bending portion 17A and theflexible portion 18A bend, the gap 90 is hardly increased between thetube proximal end portion 29 and the outer peripheral portion of theinsertion section 2 or the member disposed on the outer peripheralportion of the insertion section 2.

Moreover, in this modification, the attachment unit 25 is extended alongthe longitudinal axis C from the position to the outer peripheraldirection side of the bending tube connecting portion 21A to theposition to the outer peripheral direction side of the intermediateconnecting portion 22A. That is, the substantially entire attachmentunit 25 is placed to the outer peripheral direction side of the passivebending portion 17A. With the above-described configuration, theattachment unit 25 is not placed to the outer peripheral direction sideof the flexible portion 18A provided in the part on the proximaldirection side of the insertion section 2. Therefore, the flexibility ofthe flexible portion 18A can be prevented from being reduced.

Therefore, based on the second modification, to avoid a reduction inflexibility of the part on the proximal direction side of the insertionsection 2, placing at least a part of the attachment unit 25 to theouter peripheral direction side of the passive bending portion (17 or17A) can suffice.

Additionally, as a third modification, as shown in FIG. 9A and FIG. 9B,an air supply tube 102 configured to supply air to the gap 90 betweenthe tube main body 26 and the outer peripheral portion of the insertionsection 2 and to suck air from the gap 90 may be provided. The airsupply tube 102 is extended to the outside of the operation section 3from the gap 90 through the outer peripheral portion of the firstflexible portion 18, the inside of the insertion main body 13 (theinsertion section 2), and the inside of the operation section 3.Further, the other end of the air supply tube 102 is connected to an airsupply unit 103. The air supply unit 103 is electrically connected tothe control unit 10. When the air supply unit 103 is driven, air supplyto the gap 90 and air suction from the gap 90 are carried out. With theair supply and the air suction in the gap 90, the dimension (D1 or D2)from the longitudinal axis C to the outer peripheral end of the finportion 27 varies. As a result, the dimension (D1 or D2) from thelongitudinal axis C to the outer peripheral end of the fin portion 27 isadjusted in accordance with an inner diameter of the lumen. Therefore,in each of the lumens having various inner diameters, the outerperipheral end of the fin portion 27 can be brought into contact withthe paries.

Additionally, as a fourth modification, as shown in FIG. 10, twodifferent types of attachment units 25A and 25B may be selectivelyattached to the insertion section 2. The attachment unit (a firstattachment unit) 25A has a dimension L1 in the directions parallel tothe longitudinal axis C. Further, in a state that the external force inthe directions parallel to the longitudinal axis C is not exerted, thedimension of attachment unit 25A from the longitudinal axis C to theouter peripheral end of the fin portion 27 is D3. The attachment unit (asecond attachment unit) 25B has a dimension L2 smaller than dimension L1in the directions parallel to the longitudinal axis C. Furthermore, inthe state that the external force in the directions parallel to thelongitudinal axis C is not exerted, the dimension of attachment unit 25Bfrom the longitudinal axis C to the outer peripheral end of the finportion 27 is a dimension D4 greater than dimension D3. When such aconfiguration is adopted, the attachment unit (25A or 25B) can beselectively attached to the insertion section 2 in accordance with atype of patient or a type of lumen.

Moreover, as a fifth modification, as shown in FIG. 11, two fin portions27A and 27B may be spirally extended on the outer peripheral portion ofthe tube main body 26 of the attachment unit 25. Here, an acute angle α1of the fin portion (a first fin portion) 27A with respect to thelongitudinal axis C is the same as an acute angle α2 of the fin portion(a second fin portion) 27B with respect to the longitudinal axis C.Additionally, the fin portion 27A is apart from the fin portion 27B inthe directions parallel to the longitudinal axis C by a distancecorresponding to a dimension S, and it is extended at the same pitch asthat of the fin portion 27B. As a result, the fin portion 27A and thefin portion 27B are extended without overlapping.

When the two fin portions 27A and 27B are provided, a contact areabetween the fin portions 27A and 27B and the paries is increased.Therefore, when the attachment unit 25 rotates, the propulsive force inone of the directions parallel to the longitudinal axis C is furtherincreased. As a result, the insertability and the removability of theinsertion section 2 when passing through the lumen are further improved.

Further, as a sixth modification, as shown in FIG. 12, two attachmentunits 25C and 25D may be attached to the insertion section 2 at the sametime. In this modification, an attachment unit (a second attachmentunit) 25D is provided to the proximal direction side of an attachmentunit (a first attachment unit) 25C. When the number of the attachmentunits 25C and 25D attached to the insertion section 2 is increased,propulsive force in one of the directions parallel to the longitudinalaxis C is further increased at the time of simultaneous rotation of theattachment units 25C and 25D. As a result, the insertability and theremovability of the insertion section 2 when passing through the lumenare further improved.

Furthermore, in the first embodiment, the tube main body 26 of theattachment unit 25 is made of a resin, and the fin portion 27 is formedof rubber, but the present invention is not restricted thereto. Forexample, as a seventh modification, as shown in FIG. 13, the tube mainbody 26 may include a metal helical tube 105, a metal reticular tube 106that covers the outer peripheral direction side of the helical tube 105,and a resin envelope 107 that covers the outer peripheral direction sideof the reticular tube 106. That is, the tube main body 26 has the samelayer configuration as the first flexible portion 18 and the secondflexible portion 19. In this modification, the fin portion 27 is made ofa resin, and it is integrally formed of the envelope 107 of the tubemain body 26.

Second Embodiment

A second embodiment according to the present invention will now bedescribed with reference to FIG. 14 and FIG. 15. The second embodimentis obtained by modifying the configuration of the first embodiment asfollows. It is to be noted that like reference numerals denote partsequal to those in the first embodiment and a description thereof will beomitted.

FIG. 14 is a view showing a member insertion portion 72 according tothis embodiment. As shown in FIG. 14, in this embodiment, a linearmember 83 is extended from a rotary gear 63 along a channel 73 like thefirst embodiment. A switching connecting portion 111 is provided at anend of the linear member 83 on the opposite side of the rotary gear 63.In this embodiment, the rotary gear 63, the linear member 83, and theswitching connecting portion 111 constitute a gear unit 110.

Further, a drive unit 113 including a motor 75 or a manual rotation unit117 including a manual rotation member 118 configured to manuallyperform rotational operation is selectively attached to a memberinsertion portion 72 as an attachment portion. In a state that the driveunit 113 is attached to the member insertion portion 72, the switchingconnecting portion 111 connects the linear member 83 to the motor 75.Furthermore, in a state that the manual rotation unit 117 is attached tothe member insertion portion 72, the switching connecting portion 111connects the linear member 83 to the manual rotation member 118. Thatis, the switching connecting portion 111 selectively connects the linearmember 83 to the motor 75 as a drive member or the manual rotationmember 118. As a result, the drive unit 113 or the manual rotation unit117 is selectively connected to the gear unit 110.

In a state that the drive unit 113 is connected to the gear unit 110,the linear member 83 and the rotary gear 63 rotate about a gear axis Rby the rotational drive of the motor 75. When the rotary gear 63rotates, the rotor 61 and the attachment unit 25 rotate about thelongitudinal axis C with respect to the insertion main body 13.Moreover, in a state that the manual rotation unit 117 is connected tothe gear unit 110, the linear member 83 and the rotary gear 63 rotateabout the gear axis R by the rotational operation of the manual rotationmember 118. As a result, the rotor 61 and the attachment unit 25 rotateabout the longitudinal axis C with respect to the insertion main body13.

FIG. 15 is a view showing a state that the motor 75 is attached to themember insertion portion 72. As shown in FIG. 15, the motor 75 includesa motor main body 121 provided to be fixed to the member insertionportion 72, and a rotary shaft portion 122 which is configured to rotatewith respect to the motor main body 121 in a state that the motor 75 isdriven to rotate. In a state that the drive unit 113 is connected to thegear unit 110, the linear member 83 is connected to the rotary shaftportion 122 through the switching connecting portion 111. Furthermore,an elastic member 123 is provided between the member insertion portion72 of the operation section 3 and the motor main body 121 of the motor75. The elastic member 123 maintains water-tightness between the memberinsertion portion 72 and the motor 75. As a result, inflow of a liquidinto the operation section 3 from the outside is avoided.

Moreover, in a state that the manual rotation member 118 is attached tothe member insertion portion 72, the elastic member 123 maintainswater-tightness between the member insertion portion 72 and the manualrotation member 118. As a result, inflow of the liquid into theoperation section 3 from the outside is avoided. With theabove-described configuration, the motor 75 or the manual rotationmember 118 can be cleaned and sterilized while being attached to themember insertion portion 72.

A function of an endoscope 1 according to this embodiment will now bedescribed. When inserting or removing the insertion section 2 into orfrom a lumen, the motor 75 as the drive member is driven to rotate. As aresult, the attachment unit 25 rotates about the longitudinal axis C,and propulsive force in one of the directions parallel to thelongitudinal axis C is exerted with respect to the insertion section 2.At this time, a problem, for example, a failure may possibly occur inthe motor 75 and the motor 75 cannot be driven to rotate. In this case,the attachment unit 25 does not rotate, and the propulsive force in thedirections parallel to the longitudinal axis C does not act on theinsertion section 2.

Therefore, in this embodiment, when a problem occurs in the motor 75,the switching connecting portion 111 of the gear unit 110 is removedfrom the motor 75, and the motor 75 is removed from the member insertionportion 72. Further, the manual rotation member 118 is attached to themember insertion portion 72, and the linear member 83 is connected tothe manual rotation member 118 through the switching connecting portion111. As a result, the gear unit 110 is connected to the manual rotationunit 117. Furthermore, rotational operation is performed in the manualrotation member 118. As a result, the attachment unit 25 rotates, andthe propulsive force in one of the directions parallel to thelongitudinal axis C is exerted with respect to the insertion section 2.As described above, in this embodiment, it is possible to cope with aproblem of the motor 75 which is the drive member.

Moreover, the switching connecting portion 111, provided at the endportion of the linear member 83 on the opposite side of the rotary gear63, selectively connects the linear member 83 to the motor 75 as thedrive member or the manual rotation member 118. Therefore, removal ofthe motor 75 or the manual rotation member 118 from the linear member 83and connection of the linear member 83 to the motor 75 or the manualrotation member 118 can be facilitated.

Therefore, in the thus configured endoscope 1, in addition to the sameeffects as those of the first embodiment, the following effects areexerted. That is, in the embodiment 1, the drive unit 113 or the manualrotation unit 117 is selectively connected to the gear unit 110including the rotary gear 63. Therefore, when a problem occurs in themotor 75, the switching connecting portion 111 of the gear unit 110 isremoved from the motor 75, and the motor 75 is removed from the memberinsertion portion 72. Further, the manual rotation member 118 isattached to the member insertion portion 72, and the linear member 83 isconnected to the manual rotation member 118 by the switching connectingportion 111. Furthermore, a rotational operation is performed in themanual rotation member 118. As a result, the attachment unit 25 rotates,and the propulsive force in one of the directions parallel to thelongitudinal axis C is exerted with respect to the insertion section 2.As described above, in the endoscope 1, it is possible to appropriatelycope with a problem in the motor 75 which is the drive member.

Moreover, in the endoscope 1, the linear member 83 is selectivelyconnected to the motor 75 as the drive member or the manual rotationmember 118 by the switching connecting portion 111, which is provided atthe end portion of the linear member 83 on the opposite side of therotary gear 63. Therefore, removal of the motor 75 or the manualrotation member 118 from the linear member 83 and connection of thelinear member 83 to the motor 75 or the manual rotation member 118 canbe facilitated.

Additionally, in the endoscope 1, the elastic member 123 holds thewater-tightness between the member insertion portion 72 and the motor 75or the manual rotation member 118 attached to the member insertionportion 72. As a result, inflow of a liquid into the operation section 3from the outside can be avoided. With the above-described configuration,the motor 75 or the manual rotation member 118 can be cleaned andsterilized while being attached to the member insertion portion 72.

(Modification of Second Embodiment)

It is to be noted that the motor 75 or the manual rotation member 118 isattached to the member insertion portion 72 in the second embodiment,but the present invention is not restricted thereto. For example, as afirst modification, as shown in FIG. 16, the linear member 83 may beextended to the outside of the operation section 3 from a memberinsertion opening 71. In this modification, the switching connectingportion 111 selectively connects the linear member 83 to the motor 75 orthe manual rotation member 118 outside the operation section 3.

Third Embodiment

A third embodiment according to the present invention will now bedescribed with reference to FIG. 17 and FIG. 18. The third embodiment isobtained by modifying the configuration of the first embodiment asfollows. It is to be noted that like reference numerals denote partsequal to those in the first embodiment and a description thereof will beomitted.

FIG. 17 is a view showing a configuration of an insertion section 2 andan attachment unit 25 near a bending tube connecting portion 21. Asshown in FIG. 17, an insertion main body 13 according to this embodimentincludes a first bending portion envelope 45A and a second bendingportion envelope 45B. In an active bending portion 16, the first bendingportion envelope 45A covers an outer peripheral direction side of abending portion reticular tube 43. Furthermore, in a passive bendingportion 17, the second bending portion envelope 45B covers the outerperipheral direction side of the bending portion reticular tube 43. Ametal intermediate envelope 125 is provided between the first bendingportion envelope 45A and the second bending portion envelope 45B. In thebending tube connecting portion 21, the intermediate envelope 125 coversthe outer peripheral direction side of the bending portion reticulartube 43.

In this embodiment, a first outer surface portion 127 of the insertionmain body 13 is formed of the first bending portion envelope 45A and afirst flexible portion envelope 49. A tube main body 26 of theattachment unit 25 is placed to the outer peripheral direction side ofthe first outer surface portion 127. Moreover, a second outer surfaceportion 128 of the insertion main body 13 is formed of the intermediateenvelope 125. A tube distal end portion 28 of the attachment unit 25 isplaced to the outer peripheral direction side of the second outersurface portion 128. The first bending portion envelope 45A is made of,for example, fluorine-containing rubber, and the first flexible portionenvelope 49 made of a resin, whereas the intermediate envelope 125 ismade of a metal. Therefore, the second outer surface portion 128 hashigher strength against friction than the first outer surface portion127. That is, the first outer surface portion 127 serves as alow-strength outer surface portion, and the second outer surface portion128 serves as a high-strength outer surface portion having higherstrength against friction than the first outer surface portion 127.

In the tube distal end portion 28, a distal side gap reduction portion91 eliminates a gap 90 between the attachment unit 25 and the outerperipheral portion of the insertion section 2 or a member disposed onthe outer peripheral portion of the insertion section 2, or reduces thegap 90 to be smaller than the part to the inner peripheral directionside of the tube main body 26. Therefore, when the attachment unit 25rotates, friction is apt to occur between the tube distal end portion 28and the second outer surface portion 128. Therefore, in this embodiment,the strength of the second outer surface portion 128 against friction isincreased by providing the intermediate envelope 125. Therefore, thesecond outer surface portion 128 is hardly damaged by the frictionproduced when the attachment unit 25 rotates.

Additionally, the metal intermediate envelope 125 (the second outersurface portion 128) is placed to the bending tube connecting portion 21(a first connecting tube portion) less flexible than the active bendingportion (a first tubular portion) 16 and the passive bending portion 17(a second tubular portion). The bending tube connecting portion 21 isnot bent by the external force in the directions perpendicular to thelongitudinal axis C. Therefore, quality of the intermediate envelope 125can be readily maintained.

FIG. 18 is a view showing a configuration of the insertion section 2 andthe attachment unit 25 near a flexible tube connecting portion 23. Asshown in FIG. 18, like the first embodiment, a metal connecting mouthring 58 that connects a first flexible portion 18 to a second flexibleportion 19 is provided to the flexible tube connecting portion 23. Athird outer surface portion 129 of the insertion main body 13 is formedof the connecting mouth ring 58. A tube proximal end portion 29 of theattachment unit 25 is placed to the outer peripheral direction side ofthe third outer surface portion 129. Since the connecting mouth ring 58is made of a metal, the third outer surface portion 129 has higherstrength against friction than the first outer surface portion 127. Thatis, the first outer surface portion 127 serves as a low-strength outersurface portion, and the third outer surface portion 129 serves as ahigh-strength outer surface portion having higher strength againstfriction than the first outer surface portion 127.

Like the first embodiment, a rotor (a second rotor) 61 and a rotary gear63 are attached to the connecting mouth ring 58. The connecting mouthring 58 functions as a partition member configured to separate therotary gear 63 and a gear portion 65 of the rotor 61 from each built-inextended member 33. A gear arrangement cavity 64, in which the rotarygear 63 is placed, is formed between the rotor 61 and the connectingmouth ring 58. A linear member 83 is extended in the insertion main body13 (the insertion section 2) and the operation section 3. One end of thelinear member 83 is connected to a motor 75 attached to a memberinsertion portion 72. It is to be noted that, as different from thefirst embodiment, a channel tube 69 is not provided and a channel 73 isnot formed in this embodiment.

A gear connecting portion 131 that connects the rotary gear 63 to thelinear member 83 is provided at the other end of the linear member 83.The gear connecting portion 131 connects the rotary gear 63 with thelinear member 83 in the gear arrangement cavity 64. Furthermore, thegear connecting portion 131 is attached to the connecting mouth ring 58through an elastic member 132. When the elastic member 132 maintains thewater-tightness between the gear connecting portion 131 and theconnecting mouth ring 58, inflow of a liquid into the insertion mainbody 13 from the gear arrangement cavity 64 can be avoided.

Here, the elastic member 132 is smaller than the elastic member 62according to the first embodiment that maintains the water-tightnessbetween the rotor 61 and the connecting mouth ring 58. Therefore, whenthe attachment unit 25 rotates, friction between the gear connectingportion 131 and the elastic member 132 is smaller than frictiongenerated between the rotor 61 and the elastic member 62 in the firstembodiment. Therefore, as compared with the first embodiment, driveforce of rotating the attachment unit 25 can be decreased.

Additionally, in a tube proximal end portion 29, a proximal side gapreduction portion 92 eliminates the gap 90 between the attachment unit25 and the outer peripheral portion of the insertion section 2 or amember disposed on the outer peripheral portion of the insertion section2, or reduces the gap 90 to be smaller than a part to the innerperipheral direction side of the tube main body 26. Further, the rotor61 rotates with respect to the connecting mouth ring 58. Therefore, whenthe attachment unit 25 rotates, friction is apt to occur between thetube proximal end portion 29 and the rotor 61, and, the third outersurface portion 129. Therefore, in this embodiment, the strength of thethird outer surface portion 129 against friction is increased byproviding the connecting mouth ring 58. Therefore, the third outersurface portion 129 is hardly damaged by friction that occurs when theattachment unit 25 rotates.

Furthermore, since the metal connecting mouth ring 58 (the third outersurface portion 129) is placed to the flexible tube connecting portion23 (a second connecting tube portion) less flexible than the firstflexible portion (a third tubular portion) 18 and the second flexibleportion 19 (a fourth tubular portion). The flexible tube connectingportion 23 is not bent by the external force in the directionsperpendicular to the longitudinal axis C. Therefore, quality of theconnecting mouth ring 58 can be readily maintained.

Therefore, in the thus configured endoscope 1, in addition to the sameeffects as those of the first embodiment, the following effects areexerted. That is, in the tube distal end portion 28 of the endoscope 1,the distal side gap reduction portion 91 eliminates the gap 90 betweenthe attachment unit 25 and the outer peripheral portion of the insertionsection 2 or the member disposed on the outer peripheral portion of theinsertion section 2, or reduces the gap 90 to be smaller than the regionto the inner peripheral direction side of the tube main body 26.Therefore, when the attachment unit 25 rotates, friction is apt to occurbetween the tube distal end portion 28 and the second outer surfaceportion 128. Therefore, the second outer surface portion 128 of theinsertion main body 13 has higher strength against friction than thefirst outer surface portion 127. Therefore, it is possible toeffectively avoid damage to the second outer surface portion 128 due tofriction that occurs when the attachment unit 25 rotates.

Furthermore, in the tube proximal end portion 29 of the endoscope 1, theproximal side gap reduction portion 92 eliminates the gap 90 between theattachment unit 25 and the outer peripheral portion of the insertionsection 2 or the member disposed on the outer peripheral portion of theinsertion unit 2, or reduces the gap 90 to be smaller than the part tothe inner peripheral direction side of the tube main body 26. Moreover,the rotor 61 rotates with respect to the connecting mouth ring 58.Therefore, when the attachment unit 25 rotates, friction is apt to occurbetween the tube proximal end portion 29 and the rotor 61, and, thethird outer surface portion 129. Therefore, the third outer surfaceportion 129 of the insertion main body 13 has higher strength againstfriction than the first outer surface portion 127. Therefore, it ispossible to effectively avoid damage of the third outer surface portion129 due to friction that occurs when the attachment unit 25 rotates.

Additionally, in the endoscope 1, the gear connecting portion 131connects the rotary gear 63 to the linear member 83 in the geararrangement cavity 64. Further, the gear connecting portion 131 isattached to the connecting mouth ring 58 through the elastic member 132.When the elastic member 132 maintains the water-tightness between thegear connecting portion 131 and the connecting mouth ring 58, inflow ofa liquid from the gear arrangement cavity 64 into the insertion mainbody 13 can be avoided.

Furthermore, in the endoscope 1, the elastic member 132 is smaller thanthe elastic member 62 according to the first embodiment that maintainsthe water-tightness between the rotor 61 and the connecting mouth ring58. Therefore, when the attachment unit 25 rotates, friction between thegear connecting portion 131 and the elastic member 132 is reduced.Therefore, drive force of rotating the attachment unit 25 can bereduced.

Moreover, in the endoscope 1, the metal intermediate envelope 125 (thesecond outer surface portion 128) is placed to the bending tubeconnecting portion 21 (the first connecting tube portion) less flexiblethan the active bending portion (the first tubular member) 16 and thepassive bending portion 17 (the second tubular member). The bending tubeconnecting portion 21 is not bent by the external force in thedirections perpendicular to the longitudinal axis C. Therefore, thequality of the intermediate envelope 125 can be easily maintained.Additionally, the metal connecting mouth ring 58 (the third outersurface portion 129) is placed to the flexible tube connecting portion23 (the second connecting tube portion) less flexible than the firstflexible portion (the third tubular portion) 18 and the second flexibleportion 19 (the fourth tubular portion). The flexible tube connectingportion 23 is not bent by the external force in the directionsperpendicular to the longitudinal axis C. Therefore, the quality of themetal connecting mouth ring 58 can be easily maintained.

(Modification of Third Embodiment)

It is to be noted that the second outer surface portion 128 is formed ofthe intermediate envelope 125 in the third embodiment, but the presentinvention is not restricted thereto. For example, as a firstmodification, as shown in FIG. 19, a metal ring 135 may be fixed to theouter peripheral portion of the bending portion envelope 45. In thiscase, the second outer surface portion 128, having higher strengthagainst friction than that of the first outer surface portion 127, isformed of the ring 135.

Further, as a second modification, as shown in FIG. 20, the insertionsection 2 may includes a rotor (a first rotor) 101 to which the tubedistal end portion 28 is fixed without a gap. In this modification, therotor 101 is placed to the outer peripheral direction side of the secondouter surface portion 128. When the attachment unit 25 rotates, frictionis apt to occur between the tube distal end portion 28 and the rotor101, and, the second outer surface portion 128. Therefore, in thismodification, strength of the second outer surface portion 128 againstfriction is set higher than that of the first outer surface portion 127.Therefore, the second outer surface portion 128 is hardly damaged due tofriction that occurs when the attachment unit 25 rotates.

Furthermore, when the attachment unit 25 rotates, friction is apt tooccur between the tube proximal end portion 29 and the third outersurface portion 129. Therefore, in this modification, strength of thethird outer surface portion 129 against friction is set higher than thatof the first outer surface portion 127. Therefore, the third outersurface portion 129 is hardly damaged due to friction that occurs whenthe attachment unit 25 rotates.

Fourth Embodiment

A fourth embodiment according to the present invention will now bedescribed with reference to FIG. 21 to FIG. 22. The fourth embodiment isobtained by modifying the configuration of the first embodiment asfollows. It is to be noted that like reference numerals denote partsequal to those in the first embodiment, and a description thereof willbe omitted.

FIG. 21 is a view showing a configuration of an insertion section 2 andan attachment unit 25 near a flexible tube connecting portion 23. FIG.22 is a cross-sectional view taken along a line 22-22 in FIG. 21. Asshown in FIG. 21 and FIG. 22, in this embodiment, the insertion section2 does not include a rotor 61 that rotates about a longitudinal axis Cwith respect to an insertion main body 13. Further, a gear portion 137that meshes with a rotary gear 63 of a gear unit 110 is provided to atube proximal end portion 29 of the attachment unit 25. With such aconfiguration, the rotary gear 63 is placed on an outer peripheralportion of the insertion section 2, and a gear arrangement portion 138is provided on the outer peripheral portion of the insertion section 2.That is, in a state that the attachment unit 25 is removed from theinsertion section 2, the rotary gear 63 is exposed to the outside.

Furthermore, a groove-shaped portion 139 is provided in the rotary gear63 along a gear axis R. The groove-shaped portion 139 is formed into asubstantially hexagonal shape in a cross section perpendicular to thegear axis R.

In a tube proximal end portion 29, a proximal side gap reduction portion92 eliminates a gap 90 between the attachment unit 25 and a connectingmouth ring 58 or the rotary gear 63, or reduces the gap 90 to be smallerthan a part to an inner peripheral direction side of a tube main body26. That is, the proximal side gap reduction portion 92 eliminates thegap 90 between the attachment unit 25 and the outer peripheral portionof the insertion section 2 or a member disposed on the outer peripheralportion of the insertion section 2, or reduces the gap 90 to be smallerthan the part to the inner peripheral direction side of the tube mainbody 26. Moreover, the tube proximal end portion 29 meshes with therotary gear 63 attached to the outer peripheral portion of the insertionsection 2 without the gap 90 by the proximal side gap reduction portion92. Therefore, when the rotary gear 63 rotates about the gear axis R,the attachment unit 25 rotates about the longitudinal axis C withrespect to the insertion main body 13.

A connection pipe 67, a channel tube 68, and a member insertion portion72 define a channel 73 from a gear arrangement portion 138 on the outerperipheral portion of the insertion section 2. That is, the memberinsertion portion 72, the channel tube 68, and the connection pipe 67constitute a channel defining portion that defines the channel 73. Thechannel 73 is extended to the gear arrangement portion 138 from a memberinsertion opening 71 of an operation section 3. That is, the channel 73is extended from the outer surface of the operation section 3 throughthe inside of the operation section 3 and the inside of the insertionsection 2 (an insertion main body 13). Additionally, in the geararrangement portion 138 where the rotary gear 63 is placed, an openingis formed on the outer peripheral portion of the insertion section 2.

In this embodiment, the rotary gear 63 is placed on the outer peripheralportion of the insertion section 2, and the gear arrangement portion 138is provided on the outer peripheral portion of the insertion section 2.Therefore, in a state that the attachment unit 25 is removed from theinsertion section 2, the rotary gear 63 is exposed to the outside.Therefore, the rotary gear 63 can be readily cleaned and sterilized.

Further, the channel 73 is extended from the outer surface of theoperation section 3 to the gear arrangement portion 138 on the outerperipheral portion of the insertion section 2. That is, both ends of thechannel 73 are opened with respect to the outside of the insertionsection 2 and the operation section 3. Therefore, even if a liquid flowsinto the channel 73, the liquid hardly stays in the channel 73.Therefore, inflow of the liquid into the channel 73 in the insertionmain body 13 does not have to be avoided. In this embodiment, since awaterproof elastic member is not provided, when the attachment unit 25rotates, friction that acts on a linear member 83 and the tube proximalend portion 29 is reduced. Therefore, drive force of rotating theattachment unit 25 can be reduced. Accordingly, a motor 75 as a drivemember and the linear member 83 are reduced in size, and the endoscope 1itself is also reduced in size.

Therefore, in the thus configured endoscope 1, in addition to the sameeffects as those of the first embodiment, the following effects areexerted. That is, in the endoscope 1, the rotary gear 63 is placed onthe outer peripheral portion of the insertion section 2, and the geararrangement portion 138 is provided on the outer peripheral portion ofthe insertion section 2. Therefore, in a state that the attachment unit25 is removed from the insertion section 2, the rotary gear 63 isexposed to the outside. Therefore, the rotary gear 63 can be readilycleaned and sterilized.

Furthermore, the channel 73 is extended from the outer surface of theoperation section 3 to the gear arrangement portion 138 on the outerperipheral portion of the insertion section 2. That is, both ends of thechannel 73 are opened with respect to the outside of the insertionsection 2 and the operation section 3. Therefore, even if a liquid flowsinto the channel 73, the liquid hardly stays in the channel 73.Therefore, inflow of the liquid into the channel 73 in the insertionmain body 13 does not have to be avoided. Since the waterproof elasticmember is not provided, when the attachment unit 25 rotates, frictionthat acts on the linear member 83 and the tube proximal end portion 29is reduced. Therefore, drive force of rotating the attachment unit 25can be reduced. Accordingly, the motor 75 as a drive member and thelinear member 83 are reduced in size, and the endoscope 1 itself is alsoreduced in size.

(Modification of Fourth Embodiment)

As a first modification of the fourth embodiment, as shown in FIG. 23, adrive unit 113 or a manual rotation unit 117 may be selectivelyconnected to the gear unit 110 including the rotary gear 63. The driveunit 113 includes a motor 75 as a drive member, and a first linearmember 83A. In a state that the motor 75 is attached to a memberinsertion portion 72 as an attachment portion, the first linear member83A is extended toward the rotary gear 63 through the inside of theoperation section 3 and the inside of the insertion section 2. Further,the drive unit 113 includes a first switching connecting portion 141Athat connects the rotary gear 63 to the first linear member 83A in thegear arrangement portion 138. FIG. 24 is a cross-sectional view takenalong a line 24-24 in FIG. 23. As shown in FIG. 24, the first switchingconnecting portion 141A is formed into a substantially hexagonal shapeassociated with the groove-shaped portion of the rotary gear 63 in thecross section perpendicular to the gear axis R. When the first switchingconnecting portion 141A is inserted into the groove-shaped portion 139,the rotary gear 63 is connected to the first linear member 83A. As aresult, the gear unit 110 is connected to the drive unit 113.

The manual rotation unit 117 includes a manual rotation member 118 and asecond linear member 83B. In a state that the manual rotation member 118is attached to the member insertion portion 72 as the attachmentportion, the second linear member 83B is extended toward the rotary gear63 through the inside of the operation section 3 and the inside of theinsertion section 2. Furthermore, the manual rotation unit 117 includesa second switching connecting portion 141B that connects the rotary gear63 to the second linear member 83B in the gear arrangement portion 138.Like the first switching connecting portion 141A, the second switchingconnecting portion 141B is formed into a substantially hexagonal shapeassociated with the groove-shaped portion 139 of the rotary gear 63 inthe cross section perpendicular to the gear axis R. When the secondswitching connecting portion 141B is inserted into the groove-shapedportion 139, the rotary gear 63 is connected to the second linear member83B. As a result, the gear unit 110 is connected to the manual rotationunit 117.

In this modification, the drive unit 113 or the manual rotation unit 117is selectively connected to the gear unit 110 including the rotary gear63. As a result, when a problem occurs in the motor 75, the firstswitching connecting portion 141A of the drive unit 113 is removed fromthe rotary gear 63, and the drive unit 113 is removed from the memberinsertion portion 72. Moreover, the manual rotation member 118 isattached to the member insertion portion 72, and the second linearmember 83B is connected to the rotary gear 63 through the secondswitching connecting portion 141B. Additionally, a rotational operationis carried out in the manual rotation member 118. As a result, theattachment unit 25 rotates, and propulsive force in one of thedirections parallel to the longitudinal axis C acts on the insertionsection 2. As described above, in the endoscope 1 according to thismodification, it is possible to appropriately cope with a problem in themotor 75 which is the drive member. Further, it is also possible to copewith a problem in the first linear member 83A of the drive unit 113.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details and representative embodiments shownand described herein. Accordingly, various modifications may be madewithout departing from the spirit or scope of the general inventiveconcept as defined by the appended claims and their equivalents.

What is claimed is:
 1. An endoscopic device comprising: an endoscope,the endoscope including an insertion main body which extends along alongitudinal axis, the insertion main body including a low-strengthouter surface portion, and a high-strength outer surface portion whichis harder than the low-strength outer surface portion and which therebyhas a higher strength against friction than the low-strength outersurface portion, a cavity being formed inside the insertion main body,the cavity being opened with respect to an outside of the insertion mainbody on the high-strength outer surface; a rotary gear which is attachedto the insertion main body and which is located within the cavity of theinsertion main body; a rotor which is attached to an outer peripheraldirection side of the high-strength outer surface of the insertion mainbody, the rotor including a gear portion which is provided on an innerperipheral portion of the rotor and which is configured to mesh with therotary gear in the cavity, the rotor being configured to rotate withrespect to the insertion main body about the longitudinal axis when therotary gear meshed with the gear portion of the rotor rotates; and anattachment unit which is attached to the outer peripheral direction sideof the insertion main body and rotor, the attachment unit including: atube main body which is extended along the longitudinal axis in a statethat a gap is provided between the tube main body and an outerperipheral portion of the insertion main body or a member disposed tothe outer peripheral portion of the insertion main body, and which isplaced to the outer peripheral direction side of the low-strength outersurface portion when the attachment unit is attached to the outerperipheral direction side of the insertion main body and the rotor; afin portion which is spirally extended on an outer peripheral portion ofthe tube main body about the longitudinal axis; a tube proximal endportion which is provided to a proximal direction side of the tube mainbody, and which constitutes a proximal end of the attachment unit, anouter diameter of the tube proximal end portion being gradually reducedas directing toward the proximal direction, the tube proximal endportion being configured to be placed to a distal direction side withrespect to a proximal end of the insertion main body and placed to theouter peripheral direction side of the high-strength outer surfaceportion when the attachment unit is attached to the outer peripheraldirection side of the insertion main body and the rotor; and a proximalside gap reducing portion which is provided on an inner peripheralportion of the tube proximal end portion, and which is configured toeliminate the gap or reduce the gap between the tube proximal endportion and the outer peripheral portion of the insertion main body orthe member disposed to the outer peripheral portion of the insertionmain body as compared with a part to an inner peripheral direction sideof the tube main body, the proximal side gap reducing portion contactingthe rotor along an entire circumference of the rotor without the gap sothat the attachment unit is fixed to the rotor and the attachment unitis attached to the insertion main body and the rotor, the attachmentunit being configured to rotate integral with the rotor with respect tothe insertion main body about the longitudinal axis when the attachmentunit is fixed to the rotor and the rotary gear meshed with the gearportion of the rotor rotates, the tube proximal end portion beingconfigured to rotate integral with the tube main body when theattachment unit rotates about the longitudinal axis.
 2. The endoscopicdevice according to claim 1, wherein the attachment unit includes a tubedistal end portion which is provided to a distal direction side of thetube main body, and which constitutes a distal end of the attachmentunit, the tube distal end portion including a distal side gap reducingportion which is configured to eliminate the gap or reduce the gapbetween the tube distal end portion and the outer peripheral portion ofthe insertion main body or the member disposed to the outer peripheralportion of the insertion main body as compared with the part to theinner peripheral direction side of the tube main body, and the tubedistal end portion being configured to rotate integral with the tubemain body about the longitudinal axis with respect to the insertion mainbody when the attachment unit rotates.
 3. The endoscopic deviceaccording to claim 2, wherein at least one of the tube distal endportion and the tube proximal end portion is made of a material softerthan the tube main body.
 4. The endoscopic device according to claim 1,wherein the insertion main body includes: a first tubular portionconfigured to bend when external force acts in directions perpendicularto the longitudinal axis; a second tubular portion which is provided toa proximal direction side of the first tubular portion, and which isconfigured to bend when the external force acts in the directionsperpendicular to the longitudinal axis; and a connecting tube portion tothe outer peripheral direction side of which the tube proximal endportion and the rotor are placed, in which the high-strength outersurface portion is placed, and which connects the first tubular portionto the second tubular portion, the connecting tube portion havingflexibility lower than those of the first tubular portion and the secondtubular portion, and the connecting tube portion being configured not tobend by a function of the external force in the directions perpendicularto the longitudinal axis.
 5. The endoscopic device according to claim 4,wherein the first tubular portion is a first flexible portion, thesecond tubular portion is a second flexible portion, and the connectingtube portion is a flexible tube connecting portion which connects thefirst flexible portion to the second flexible portion.